What is TCP/IP?

TCP and IP are two different communication protocols that complement each other’s functionality.

The Internet protocol or IP delivers (routes and addresses) data packets between a source (device or application) and their destination. It makes sure that those packets arrive at the right destination. It defines the rules and formats for applications and devices to communicate and exchange those data packets on a specific network or across different connected networks. 

The transmission control protocol or TCP organizes data in a specific manner to protect them while exchanged between a client and a server. It’s a very used protocol on networks by all types of devices and applications. TCP protects data’s integrity from the sending and all the way to their delivery.

The development of these protocols (TCP/IP) happened in the 1970s. In that decade, the ARPANET became really popular, which motivated the creation of more networks to connect different organizations. Since those networks used a different protocol to send data back and forth, they could not communicate among them. The creation of a technology that could work as an intermediary to allow such communication became a need. 

The combination of TCP and IP and its official adoption as the standard protocol -in 1983-for ARPANET (Internet’s predecessor) was the solution. No matter what other protocols networks used, if they supported TCP/IP, they could communicate with all the TCP/IP networks that existed.

The two technologies, TCP and IP, became the technical base for the modern Internet to operate and grow. Actually, here the word Internet emerged, meaning “an interconnected network of networks”.

How does it work?

IP protocol works through different rules and resources, like the IP addresses. To connect to the Internet, domains and devices get a unique IP address to be identified and allowed to communicate (exchange data) with other connected devices. 

Data travel across networks separated into pieces (packets). Every piece gets IP information (IP address) attached for routers to read it and send the packet to the correct destination. Once there, the way for those packets to be handle will depend on the kind of protocol (commonly TCP or UDP) combined with the IP to transport them.

IP is a connectionless protocol. All data packets are just addressed, routed, and delivered without existing acknowledgment from the destination to the source. This lack is resolved through the Transmission Control Protocol. 

TCP secures the travel and delivery of data packets across networks through a specific process. To start, a connection between the source and the destination is required, even before the transmission of data begins. This, because TCP is a connection-oriented protocol. To work properly, it needs to guarantee this active connection until the sending and receiving of data get completed.

When the communication begins, TCP takes the sender’s messages and chops them into packets. To protect messages’ integrity, TCP numbers every packet. Then packets are ready to go to the IP layer for being transported. They will be dispatched to travel around different routers and gateways of the network to reach their destination. No matter all the packets are part of the same message, they can have different routes to arrive at the same destination.

Once they all hit their destination, TCP proceeds to re-build the message by putting all their pieces (packets) together again to make a proper delivery. 

This ideal scenario can be affected if networks face issues. Data packets could get lost in transit, duplicated, or disordered. The advantage is TCP’s functionality can detect such problems and fix them. The protocol can ask the lost packets to be re-sent to organize them again in the correct order. In case messages can’t be delivered, this is reported to the sender (source).

As you see, the Internet is a packet-switched network. All data are chopped into packets that are dispatched through lots of different routes simultaneously. When they finally hit their destination, they get re-built by TCP. And IP is in charge of the packets to be sent to the correct destination.

TCP/IP layers

TCP/IP’s most updated model includes the following four layers. All collaborate for the same purpose, the transmission of data.

• Application layer. This is the top layer, and it supplies an interface for applications and network services to communicate. It identifies participants involved in a communication, defines the access to the network’s resources, and the rules for application protocols and transport services interaction. Application layer includes all the higher-level protocols like DNS, HTTP, SSH, FTP, SNMP, SMTP, DHCP, etc.
• Transport layer. It defines the amount of data and the rate for transporting data correctly. It receives messages from the application layer, divides them into pieces, transports them, re-builds them following the proper sequence, and solves possible issues to guarantee their integrity and proper delivery. TCP operates in this layer.
• Internet layer. The internet layer, also known as the IP or network layer (not to be confused with the network access layer), is in charge of sending packets and ensuring that data is transferred as precisely as possible. As it controls the direction and pace of traffic, it is somewhat similar to a traffic controller on a road. Additionally, it supplies the procedural steps and functionalities for transferring data sequences. This layer’s protocols include IPv4, IPv6, ICMP, and ARP.
• Network access layer: The OSI model’s data link layer and physical layer are combined to form the network access layer. It outlines the process through which data is actually transferred over the network. It also covers how hardware components that physically interact with a network, such as twisted-pair copper wire, optical fiber, and coaxial cable, transmit data via optical or electrical means. The network access layer is the bottom layer in the TCP/IP model.

Understanding the TCP Handshake process

The TCP handshake process is the key to establishing a reliable connection between two devices. Known as the “three-way handshake,” this method ensures that both the sender and receiver are ready for communication before any data is transmitted. Here’s how it works step-by-step:

1. SYN (Synchronization): The process begins when the client sends a SYN packet to the server, indicating a request to start communication. This packet also contains an initial sequence number, allowing the client to mark the starting point for data transmission.

What SYN flood attack is?

2. SYN-ACK (Acknowledgment of Synchronization): The server responds with a SYN-ACK packet, acknowledging the client’s request and including its own sequence number. This signals that the server is ready to receive data and has marked its starting point for tracking data segments.
3. ACK (Final Acknowledgment): The client sends an ACK packet back to the server, acknowledging the server’s response. This final step completes the handshake, and a stable connection is established, allowing data exchange to begin.

What is the difference between TCP and IP?

TCP and IP are two different computer network protocols. Each function in the data transmission process distinguishes TCP (Transmission Control Protocol) from IP (Internet Protocol). Using IP, you may find out where data is sent (your device has an IP address). Once that IP address has been discovered, TCP guarantees accurate data delivery. The pair make up the TCP/IP protocol suite.

In other words, TCP sends and receives mail while IP sorts it. Other protocols, such as UDP (User Datagram Protocol), can transfer data within the IP system without the usage of TCP, even though the two protocols are typically regarded as a pair. But for TCP to deliver data, it needs an IP address. So another distinction between IP and TCP is this.

How to find your TCP/IP address?

To find your TCP/IP address, you can use simple methods for both your public and private IP addresses. Your public IP address, which identifies your device on the internet, can be easily found by searching “What is my IP address” in most search engines. This method displays the IP address assigned to your network by your Internet Service Provider (ISP).

For your private IP address, which is used within your local network, the process varies slightly depending on your device:

1. On Windows: Open the Command Prompt and type ipconfig. Your IP address will be listed under the appropriate network adapter as the IPv4 Address.
2. On macOS: Go to System Preferences, select Network, and choose the network you’re connected to. Your IP address will be displayed there.
3. On Linux: Open the Terminal. You can find your IP address by typing ifconfig for older distributions or ip addr for newer ones. Your IP address will be listed under the relevant network interface. 
4. On mobile devices: Go to your Wi-Fi settings. Depending on your device, you may need to tap on the network you’re connected to see details like the IP address.

For TCP ports, determining which ports are being used by your device typically involves more technical steps. You can use network utilities or command-line tools to list active ports. These tools can help you identify which ports are open and in use, which is particularly useful for network troubleshooting or configuring firewall settings.

Remember, knowing your TCP/IP address is crucial for various network tasks, from setting up your home network to troubleshooting connectivity issues.

Are my data packets secure?

The answer is no. Why? When packets are sent between devices, they are highly susceptible to being intercepted by others. So, that’s why it’s better to utilize encryption and stay away from public Wi-Fi networks when transmitting messages that need to remain secret. But unfortunately, this is sometimes not enough, which is why you need to take other actions. Here’s what they are:

1. Use Monitoring service

Systematically monitoring your network for any unusual activity. This reduces the exposure gap you have to cyberattacks. Additionally, TCP monitoring, which is a feature of the Monitoring service, uses a highly specialized protocol to examine connectivity and find communication problems on network machines. As a result, it can quickly identify issues and alert you.

2. VPN

A VPN is a great way to guarantee that your data is securely encrypted and that your packets are safeguarded throughout network traffic. A VPN can be manually configured or purchased. Furthermore, VPN comes with numerous additional advantages. For example, website unblocking, location hiding, and restricting the pages you browse from being seen by your ISP (Internet Service Provider).

3. Employ HTTPS protocols

Hypertext Transfer Protocol Secure (HTTPS), the prefix for encrypted websites, denotes the security of user activity there. Websites that begin with “HTTP” are unable to provide the same level of protection. Secure Sockets Layer (SSL) connections are indicated by the “s” in HTTPS, which stands for secure. Doing this guarantees, the data is encrypted before being delivered to a server. Therefore, to prevent packet sniffing, it is preferable only to visit websites that start with “HTTPS.”

HTTP vs HTTPS: Why every website needs HTTPS today

4. Make use of Private DNS 

Another important way to secure your data is to use Private DNS. Nowadays, using Public DNS has a lot of dangers. With Private DNS, you will be more secure against cyberattacks. Why? Because you can use Transport Layer Security (TLS) and Hypertext Transfer Protocol Secure (HTTPS). These protocols encrypt any DNS queries sent out, and DNS over these protocols is known as DoH (DNS over HTTPS) and DoT (DNS over TLS).

Advantages of TCP/IP

• It allows connecting different kinds of devices.
• It makes possible cross-platform communications among diverse networks. 
• It supports different protocols for routing.
• It offers high possibilities of scalability. You can add networks without causing trouble. 
• It supplies IP addresses to devices for identifying them.
• It’s independent of the operating system.
• It’s an open protocol. No one owns it. Everybody can use it.
• It facilitates reliable communication through data packet retransmission in case of loss, ensuring data integrity.
• It offers robust error detection and correction capabilities, enhancing data transmission reliability.

Disadvantages of TCP/IP

• To replace protocols on TCP/IP is not simple.
• It doesn’t define clearly the concepts of services, protocols, and interfaces. It can be difficult to assign a category to new technologies included in modern networks.
• It works for wide networks. It’s not suitable for small ones (PAN or LAN).
• Susceptible to security vulnerabilities if not properly secured, making encryption and other security measures essential.

TCP vs UDP

There are clear differences between the transmission control protocol (TCP) and User Datagram Protocol (UDP).

• TCP is connection-oriented, while UDP is connectionless. TCP requires an active connection to start and complete the data transmission, while UDP does not.
• TCP can recover lost packets by requiring retransmission. UDP can’t recover them.
• TCP is much slower than UDP because its process involves verification in almost every step. To guarantee the connection is active and the source ready to receive a message, to confirm delivery, etc. UDP only sends, avoiding those confirmation steps.
• TCP protects packets’ integrity efficiently. To protect this is not UDP’s strength. Its mechanism to check integrity (checksum) is less precise.

An Overview of TCP Monitoring vs UDP Monitoring

• TCP delivers ordered messages (by reassembling them based on a numerical sequence). UDP doesn’t offer this function.
• TCP guarantees the data delivery to their recipient. UDP doesn’t. 
• TCP detects and fixes possible errors better. It also supplies confirmation of delivery or reports the problem if it’s not possible to deliver. The UDP’s mechanism for error detection (checksum) is simpler and limited. It doesn’t confirm or inform about the delivery.
• TCP’s speed doesn’t solve latency. UDP really does it.
• TCP doesn’t support broadcast, while UDP really does since it does not require response or confirmation.
• The efficiency of TCP makes it ideal for applications that demand full integrity of data, zero loss (HTTP, FTP, IMAP, SSH, SMTP).
• UDP works very well for applications that require high speed and can afford data loss. Think about real-time applications like live video streaming, voice-over IP or online gaming.

Why does DNS use UDP?

TCP vs HTTP

The Transmission Control Protocol (TCP) and the Hypertext Transfer Protocol (HTTP) also differ between them. 

• TCP is used to set communication or a session between two machines (client and server). In contrast, HTTP is used for accessing data of webpages and accessing content (websites) from a web server. It’s a client-server protocol. Requests begin with the recipient, like a browser.
• TCP is a data transfer protocol. HTTP uses TCP for data transfer.
• TCP uses IP addresses, while HTTP uses hyperlinks, also known as URLs. 
• TCP is connected-oriented, while HTTP is stateless but not sessionless.
• TCP needs authentication (TCP-AO). HTTP does not.
• TCP process involves a three-way handshake, and this takes some time. HTTP is one-way communication. TCP is slower than HTTP.
• TCP uses different ports (80, 8000, 8080, etc.). HTTP usually uses the 80 port.

Conclusion

There are different protocols, and understanding their potential is basic to choose the one that better suits your network’s needs. In many cases, these technologies compliment others. TCP, independently and combined with IP, is an efficient protocol with useful functionality for the Internet and networks in general. Try them and get the best out of them!

The post TCP (Transmission Control Protocol) – What is it, and how does it work?  appeared first on ClouDNS Blog.

To be more precise, the domain name resolution is a translation process between the domain name that people use while writing in their browsers and the site’s IP addresses. You need the IP address of a site to know where it is located and load it.

A website could have both IPv4 and IPv6 addresses, and the DNS resolution of a domain name will ask for both of them. The IPv4 address will come in the form of a DNS A record, and the IPv6 will come in a DNS AAAA record.

Let’s get into the details, and see how it works, shall we?

Domain name resolution – Why is it important?

In the world of the Internet, the addresses don’t contain streets and cities. They have numbers and symbols. There are two types of addresses: IPv4 and IPv6. In order to enter a particular website, the user needs to get its IP. Instead of remembering all of the IPs of every website, we simply need to remember the domain name. The domain name is usually not hard to remember, and this makes it easier. When the user types the name of the website, the process of the domain name resolution starts.

So let’s proceed and explain the whole process of DNS resolution.

DNS resolution process

The browser of a user needs to get the IP and sends queries to the name servers. This process involves domain name resolvers. The first answer that your browser will get is the root server, then the TLD (top-level domain). The servers with the TLD of the website you want to visit (com, net, or another) will refer your queries to the next step in searching authoritative servers that know the exact IP address of the domain name. Then the domain name will be resolved.

Let’s breakdown the DNS resolution step-by-step: 

1. A user is typing a domain name like cloudns.net into their browser. The user needs an A or AAAA DNS record to resolve the domain name.
2. If your device’s cache has the IP address of cloudns.net, the domain name resolution will finish here, and the user will be able to open the website. But, if it does not, there will be more steps. The devices keep DNS records for visited sites, depending on the TTL (Time to Live) values of those DNS records. After the time they indicate, they will be deleted, and a new query needs to be performed.
3. If your computer doesn’t have the needed IP address, it will search for the answer by performing a DNS resolution query. The next destination on the way will be the recursive DNS servers of the internet services provider. They also keep a cache with DNS records of domain names that users have accessed. If the desired site’s DNS records are still there, the user will get an answer to its query and access the site. If not, there will be a series of interactive DNS queries to find the answer.
4. If the domain name resolution didn’t finish with the previous step, the recursive nameserver would search for the answer. The next step will be to ask the Root server, which is indicated with a “.” sign after the TLD (top-level domain). The Root server does not have an answer about the exact domain name, but it will provide one for the part it is responsible for – it will indicate all the nameservers for the TLD that we asked for. In our case, it will show the nameservers of .net.
5. The TLD DNS servers will have the answer of which exactly are the authoritative nameservers for the domain you are searching. The TLD servers of .net will have that information for all of the domain names that finish with .net. They will return that answer so the query can continue.
6. Now that we know where the authoritative nameserver of the domain name we want is, we can ask and get the A and AAAA records to understand the site’s IP address.
7. The Authoritative nameservers of the domain name will provide the DNS records, the DNS resolution will be made. The recursive nameserver of our ISP and our device will both save the DNS records that we obtained based on their TTL values. That way, if we soon want to visit the site again, we will save time and access the site faster.
8. Visit the site. Now with the DNS record already obtained, the user can access the site.

Do we need to care about it?

The answer is yes! For humans, the DNS resolution process is essential. And if something goes wrong, the use of the Internet by regular users would be extremely difficult. 

So we should be concerned about DNS resolution for two reasons:

1. The first one is the importance of the speed. When a user accesses your website, the DNS resolution is the first thing that happens. If your page takes too long to load and access, the user will probably leave. That’s why this process needs to be performed fast.
2. The second one is the availability. The nameserver in charge of handling your domain name needs to be trustworthy. A backup DNS service is a great technique to guarantee that your domain is always reachable by your customers.

What to do if DNS resolution is not working?

1. Check your internet connection. Many times when the domain name resolution fails, the main reason is that you are not connected to the Internet. Check your connectivity and restart your router.

2. Verify the problem is DNS-related. Before diving into DNS-specific solutions, confirm that the issue isn’t related to general connectivity. Try accessing the site with its IP address instead of its domain name. If this works, the problem likely lies with DNS resolution.

3. Obtain DNS server address automatically. Go to the network adapter and open the properties. Then search for the Internet Protocol Version 4 (TCP/IPv4) and open its properties. From there, you can click on Obtain DNS server address automatically. This will allow your computer to receive the DNS settings from the DHCP server.

4. Release and then renew the DHCP IP address. There could be an IP address conflict because of the DHCP server. What you can do as a user is to give up the IP address lease. You can do that with a command from the Command Prompt:

ipconfig /release

After that, you can renew your IP address with the following:

ipconfig /renew

Now your connectivity should be restored.

5. Flush the DNS cache of your device. You can do that by accessing the Command Prompt (as an administrator) and performing the following command:

• On Windows, open Command Prompt and type: ipconfig /flushdns
• On macOS, open Terminal and type: sudo killall -HUP mDNSResponder
• On Linux, the command varies by distribution, but a common one is: sudo systemctl restart nscd

If you had a previous IP address of a domain that is no longer available, now you have deleted it. The device performs a DNS resolution again, and it should get the new IP address.

6. Disable any VPNs or proxies. VPNs and proxies can redirect your network traffic through different servers, which may cause DNS resolution issues. Try disabling them to see if that resolves the issue.

7. Check your hosts file. The hosts file on your computer can override DNS and manually map domain names to IP addresses. Ensure there are no incorrect entries that could be causing conflicts.

• On Windows, this file is located at C:\Windows\System32\drivers\etc\hosts
• On macOS and Linux, it’s at /etc/hosts

8. Update your DNS records. If you’re managing a domain and have recently changed DNS records, it might just be a matter of waiting. DNS propagation can take up to 48 hours.

9. The last resort is to contact your ISP and tell them the problem. There is a chance that it is related to its equipment or software, and it can fix it. Or maybe it is blocking some websites on purpose. You can at least try to find an answer from it.

DNS Monitoring: Keeping Resolution on Track

DNS resolution is a silent yet critical driver of the digital world, translating domain names into IP addresses. DNS monitoring services amplify this process’s reliability by offering continuous oversight. These services rapidly identify and help rectify resolution delays or failures, ensuring users can always reach their online destinations.

DNS monitoring checks are essential in validating the seamless operation of DNS resolution, crucial for uninterrupted internet navigation. By querying specific hostnames against expected responses, these checks can swiftly flag a DNS resolution process as operational (UP) or problematic (DOWN).

For example, monitoring might run a command like:

If the response matches the expected IP, the DNS is considered healthy. This proactive measure ensures DNS performance remains robust, which is vital for network reliability and the overall user experience.

In the event of discrepancies, debugging tools, including Traceroute, assist in tracing the issue to its source, allowing for quick resolution. Thus, integrating DNS monitoring checks is a strategic move to bolster network stability and maintain consistent service delivery.

Why do we need recursive servers?

Theoretically, authoritative nameservers are enough to keep the DNS resolution process running. You can think that the only kind of DNS servers we need is authoritative, but imagine how much load they will need to take if all the complete queries get to them.

For decreasing the load and increasing the speed, there are recursive servers (DNS resolvers) that keep the DNS records with the information needed to access a particular website for a defined period of time. This time is called TTL (time to live), and the process is named DNS cache. There are such recursive servers in the internet service providers that keep the information for many websites for the period of time defined by the TTL.

To make it easier to imagine, it generally functions as a name server, acting as a go-between the customer and the authoritative DNS server. However, without it, you won’t be able to access any website that you want to reach on.

Why DNS Resolution Times Matter and How to Improve Them

DNS resolution times are a key factor in overall website performance, as they determine how quickly a user can begin accessing a webpage. If this process takes too long, it can significantly delay page load time, creating a poor user experience. Delays have a negative impact on e-commerce and business sites, where faster loading speeds directly affect sales and user engagement.

Several factors influence DNS resolution speed are the following:

• Server Proximity: The closer the authoritative DNS server is to the user, the faster the response. Many DNS providers use Anycast routing, which directs queries to the nearest server, reducing latency and speeding up resolution times.
• Caching Efficiency: When DNS records are cached effectively, repeat queries can be answered instantly from the cache, avoiding the need for a full DNS lookup. Time to Live (TTL) values determine caching duration – longer TTLs reduce query frequency for stable sites, while shorter TTLs allow for more frequent updates.
• DNS Provider Choice: A reliable, high-performance DNS provider often has better infrastructure and caching policies, as well as multiple server locations worldwide, which can reduce resolution time. Providers typically offer faster, more secure DNS resolution than ISP default options.

How DNS Resolution Works with IPv4 and IPv6 Addresses

When domain resolution occurs, it can return either IPv4 or IPv6 addresses or both, depending on the server’s configuration and the client’s capability to use either protocol. This flexibility ensures that DNS can adapt to the gradual transition from IPv4 to IPv6, supporting both legacy systems and modern networks.

The two address types serve distinct purposes:

• IPv4 (Internet Protocol version 4): IPv4 is the older protocol that uses 32-bit addresses, resulting in about 4.3 billion unique IPs. DNS A records are responsible for mapping domain names to their corresponding IPv4 addresses. However, with the explosive growth of internet-connected devices, IPv4 addresses are in short supply, which is where IPv6 steps in.
• IPv6 (Internet Protocol version 6): IPv6 was developed to provide a vast address space, using 128-bit addresses that allow for 340 undecillion unique IPs. This address space is critical for the future of the internet, as more devices connect daily. DNS AAAA records are responsible for returning IPv6 addresses for a domain. Additionally, the newer version of IP offers benefits beyond capacity, including better routing efficiency and improved security features.

Conclusion

DNS is a very useful system that saves a lot of time and makes our lives easier. After this article, you will know better what happens when you open a web page, how exactly the DNS resolution works, and what it means a domain name resolution.

The post What is Domain Name Resolution? appeared first on ClouDNS Blog.

What is the Traceroute command?

The Traceroute command (Tracert on Windows) is a small network diagnostic software that you have built-in on your device and servers for tracing the route, hop by hop to a target.
Many network administrators use the Traceroute command daily. It is a convenient tool that you can use under different operation systems – Windows (Tracert), macOS, Linux (Traceroute), and even on mobile (Android and iOS).
To access the traceroute, you will need to use the Terminal (Linux and macOS) or the Command Prompt (Windows).
You can use the Traceroute and see the full route that the packets take to their destination (domain or IP address). Apart from that, you will see the hostnames and IPs of the routers on the way and the latency, the time it takes for each device to receive and resend the data.
You can see which gateway is discarding your data, and later you can fix it.

How does it work?

When you run a traceroute, you send an IP packet containing the source and destination addresses and the time to live (TTL) for each hop. TTL in packets decreases with each hop. This is to avoid server looping issues. Furthermore, when the TTL is reached, the packet expires and is discarded. When this occurs, Traceroute returns to the sender ICMP Time Exceeded messages (RFC 792). Because small TTL settings cause packets to expire quickly, traceroute forces all routers in a packet’s path to produce the ICMP messages that identify the router.

To better visualize the traceroute’s working mechanism, you can look at the following chart.

Why use the Traceroute or the Tracert command?

The benefits of using the traceroute command or its alternative for Windows called tracert command are:

• Complete route list. You will see all the routers on the way, with their IP addresses and the time it took. You can better understand the network.
• Route timing. See how much time does it take to finish the query. Is it ok for you? What can you do to speed it up? You can have a starting point for improvements.
• It is built-in. You don’t need to install additional software, and its use is free.
• Check if you can reach a target. See if there is a connection between your device and the hostname or IP address you put in the command.
• See problematic slow router. You can see how much time it took in each hop. So you can see a spot that significantly slows your network. You can fix the problem or add more presence in the area.

When will you need it?

Here are several scenarios where using a traceroute to diagnose a problem you are having can be necessary.

• Sluggish site

Run a traceroute from your computer to your website if you find it is operating slowly. With it, you will check for networking issues between your location and the server.

• Customer timeouts for email

Run a traceroute to assess the quality of the connection to the mail server if you have problems with your mail connection. In addition, you can find your mail server IP by running the following command: “ping smtp.server.com”. It will return the IP address of the Simple Mail Transfer Protocol (SMTP) server that you need for Traceroute purposes.

How to use the Traceroute command?

Use the Traceroute command by writing the command “traceroute + domain.com / IP address” or, in the Terminal on Linux and macOS or “tracert + domain.com / IP address” in the Command Prompt on Windows.

Traceroute (Linux and macOS)

traceroute domian.com or traceroute 12.23.34.45

Tracert (Windows)

tracert domian.com or tracert 12.23.34.45

On macOS, you can also use the Traceroute utility. Press the command button + space. Then write Network Utility. Inside it, navigate to Traceroute. Write the hostname or IP address and press enter. It will show you the result.

*You can change the domain.com with another domain you want to probe, and the same goes for the IP address.

Some differences between the Traceroute command, and the Tracert exist. Check the options below.

Traceroute command vs Tracert command

Apart from the small difference between typing traceroute and the Tracert, the fact that the first works on Linux and macOS, and the second on Windows, the other significant differences are the syntax and the options.

Syntax of the traceroute and Tracert commands

traceroute [options] host_Address [pathlength] (Linux)

traceroute [options] host [packetsize] (macOS)

tracert [-d] [-h maximum_hops] [-j host-list] [-w timeout] [-R] [-S srcaddr] [-4] [-6] target_name (Windows)

Example of Traceroute (Tracert on Windows)

The name of Traceroute on Windows is Tracert. It works very similar to the version on the other operating systems.

And this is how the Traceroute command looks on Linux and macOS:

Traceroute options for Linux

If you are a Linux user (Ubuntu, Linux Mint, Manjaro, Red Hat, Debian, etc.), you can specify your traceroute command with the following options:

rDNS explained in detail

Traceroute options for Windows

You can use the Tracert command with various options to perform more precise tests. The following options work on Windows Vista, Windows 7, Windows 8, and of course, Windows 10.

Traceroute options for macOS

While the Traceroute command on macOS is very similar to its Linux version, there are small differences in their options.

Save Traceroute results for later analysis

Traceroute outputs can be long and detailed, especially when diagnosing complex networks. Saving the results for future analysis helps document network issues, allowing users to track changes, compare routes, or share the data with colleagues or support teams.

To save traceroute results to a file, simply redirect the output into a text file using the following syntax:

For Linux/macOS:

traceroute example.com > traceroute_results.txt

For Windows:

tracert example.com > tracert_results.txt

This command captures the entire output of the traceroute (or tracert) command and saves it in a file called traceroute_results.txt in the current directory. You can then review or share this file at any time, making it easier to troubleshoot ongoing network issues without needing to rerun the command.

The TTL and Traceroute

Each packet that you send contains a TTL (time to live). It is not a time but a limit of hops it can do before getting the result.

Usual limit is 30, but it can be more like 64 for example. This limit stops your data after a certain amount of hops so it won’t go forever. The IP packet will follow until it gets “time exceeded” or “port unreachable” when it gets to the host.

Starting at 30, on the next hop, it will drop to 29 and so on. If it can’t find the domain or IP that you wanted it will display a message where did it fail, so you will know where the problem is.

Distinction between Ping and Traceroute

Both Ping and Traceroute are tools for analyzing networks. However, the Traceroute is a little more advanced. For example, ping will check the connectivity between two hosts but does not reveal the route between them. On the opposite, the Traceroute shows every stop between the source and the final destination. This can be helpful when connectivity is patchy, such as when only 50% of ping attempts between two places are thriving.

So, to sum up, the Traceroute command can be used to identify connectivity issues, while ping is a quick approach to determine whether a host is reachable over a network. Both of these commands are beneficial to be aware of because knowing how they operate and what their output denotes can be very valuable when analyzing network connectivity issues.

Traceroute’s Restrictions

• It establishes the route at the interface level rather than at the router level.
• The Traceroute may not respond after crossing the maximum number of hops if there are firewalls between the source and destination routers that prevent the probe packets from being sent. Furthermore, despite the hops IP address, the router will display * (asterisk) if no response is received. Therefore, using a traceroute under these circumstances is not suggested.
• Based on the IP headers, load balancing routers can route the traffic via a number of different paths. Therefore, if we execute a traceroute in this case, it will give us an incorrect path between the origin and the goal. Accordingly, it is not advisable to employ traceroutes in this circumstance either.

Are there alternatives to the traceroute command?

Yes, there are various alternatives to the traceroute commands like MTR command, Dig command, Open Visual Traceroute, Nmap.

MTR command (Linux and macOS)

mtr domain.com

The MTR command is an improved traceroute command that can give more statistics and data for lost packets (percentage).

Dig command (Linux and macOS)

dig +trace domain.com

If you already use the Dig command, you can use it for tracing the route too.

Open Visual Traceroute (Linux, macOS, and Windows)

This one is for people who want a visual interface. It is heavier, but it can show you, in a graphical way, the route of the queries and also get Gantt graphs.

Nmap (Linux, macOS, Windows, BSD, and more)

nmap –traceroute domain.com

The results are very similar to the traceroute command.

Conclusion

By using the newly collected data, you can see if there is any problem on the route (not responsive server or very slow one) and later focus your attention to fix it. If you want to see few more tools you can check one of our previous article Тools – DNS trace, Ping, Traceroute, Nslookup, Reverse lookup.

The post Traceroute command and its options appeared first on ClouDNS Blog.

What is DHCP and DHCP server?

DHCP – Dynamic Host Configuration Protocol is a network management protocol that we use on TCP/IP networks. The DHCP server, automatically assigns IP addresses and other network configurations like subnet mask, default gateway, DNS server, and more to the connected devices so they can exchange information. DHCP lets the hosts get the necessary TCP/IP configuration data from the DHCP server.

A device makes a request for an IP address if it wants to gain access to a network that’s utilizing DHCP. The server replies and provides an IP address to the device. After that, it monitors the use of the address, and when a defined period expires, or the device shuts down, it takes it back to its pool of available IP addresses. It is kept until it has to be reassigned to a different device that wants to access the network.

Using this protocol, the network administrators don’t need to set a static IP for each device, and later reassign it to another and keep an eye on all the available IPs. They will just set up the DHCP server with all the additional network information, and it will do its work dynamically.

Why is DHCP important?

DHCP is important because it makes it really easy for network administrators to provide IP addresses to client devices on the network. It manages the pool of IP addresses automatically.
The client also does not need to do anything at all. The newly connected device will automatically ask for an IP address and get it. The person behind the device does not need to make any configurations.
Every device on a network needs the address as identification. And two devices can’t have the same IP because this will make them both unusable.

Brief History of DHCP

The Dynamic Host Configuration Protocol (DHCP) was developed in the early 1990s as a solution to the growing complexity of IP address management. Before DHCP, administrators had to manually assign static IP addresses, which was time-consuming and prone to errors, especially as networks expanded. DHCP evolved from earlier protocols like BOOTP (Bootstrap Protocol), which provided limited functionality, such as assigning IP addresses to diskless workstations.

The Internet Engineering Task Force (IETF) standardized DHCP in 1993 with the release of RFC 1531. The new protocol significantly improved BOOTP by enabling automatic, dynamic, and temporary IP address assignments, as well as better management of network configurations like subnet masks, gateways, and DNS settings. Since its introduction, it has become a fundamental part of modern network infrastructure, significantly simplifying network administration and supporting the explosive growth of devices on the internet.

Components of DHCP

Several important components work together to ensure smooth operation:

• DHCP server. The server device is in charge of answering an IP address request, providing an available IP address, storing it for the time of the lease and renewing it later. It will handle the communication with all the client devices. The server could be a computer or a part of the router.
• DHCP client. It must be present on the client devices (computer, mobile, IoT device, etc.). It will request an IP address and communicate with the DHCP server to get it with the rest of the data and confirm the process. 
• DHCP scope. This is the range of IP addresses that the DHCP server can offer to the DHCP clients. Usually, the server will auto-assign addresses, starting from the smallest number, and going to the highest. 
• Subnet. If the network is divided into pieces, there will be so-called subnets.
  Lease. That is the time period that indicates how long a client can use the assigned IP address before it expires. 
• DHCP relay. The relay is in charge of communication between the DHCP server and the client. It will listen for messages and pass them to the right place. 

How does DHCP work?

Imagine we have a network of connected devices and a DHCP server that manages the IP addresses.

• Step 1: DHCP Discover

When you connect a new device, it still does not have an IP address. It will search for an IP address. It will call over the network for a DHCP server. This request will arrive to all of the devices, and the server will also get it.

• Step 2 DHCP Offer

The DHCP hears the call, and answers with an IP address, which it оffers to the newly connected device. 

• Step 3 DHCP Request

The IP address arrives at the device. The device will accept it and will send a request to use it.

• Step 4 DHCP Pack

The server gets the accepting message from the device. It will provide the IP address to the device, together with the subnet mask and the DNS server. It will write a record with the information of the newly connected device that usually includes the MAC address of the connected device, the IP address that was assigned, and the expiration date of that IP address. The DHCP leases the IP address for a limited time only. After the time passes, the IP address will go back to the IP pool of available IP addresses and can be assigned to a new device again.

The UDP port for the communications is usually port 68 for clients and port 67 for servers. There might be some differences, depending on the vendors of network equipment, but this is how it functions in general.

IP address allocation mechanisms of DHCP

There are three ways that you can configure the DHCP server:

1. Automatic allocation. This one will automatically assign an IP per client permanently. The IP address will be designated for just one device, so if, in the future, many new devices get connected, the server could run out of IP addresses to give.
2. Dynamic allocation. This is the most common configuration. The server auto-assigns IP addresses to clients, but there is a time period. After the time expires, the client needs to ask for a new IP address again. This will prevent the running out of IPs.
3. Manual allocation. Manually the network administrator will assign the IP address to the client. 

DHCP lease duration times

In the world of networking, DHCP lease duration is a crucial concept. It simply refers to how long a device can use an IP address assigned by a DHCP server without needing to renew it. Here’s the key terminology:

• Lease allocation: When a device joins a network, the DHCP server grants it an IP address for a specified time (the lease duration).
• Lease renewal: As the lease period nears its end, the device can either renew the lease or let it expire.
• Importance: Lease duration impacts IP address management and network stability. Short leases are suitable for dynamic networks, while longer ones provide stability.
• Configuration: Network administrators can adjust lease durations to suit their network’s needs, balancing IP address management and network stability.

Understanding DHCP lease duration helps ensure efficient IP address allocation and network performance.

Benefits of DHCP

Some of the main advantages are the following:

• IP address configuration on which you can rely

DHCP makes very few errors regarding the IP address configuration. There might be some occasional errors related to the network typographic and IP conflicts when the DHCP server assigns the same IP to different devices.

• Less work for the network administrators

There are few features that admins really like about it because it makes their job easier.

You can automate the TCP/IP configuration. This can be done from one central location, without the need to move to different devices.

Additional options. It can change various additional network settings.

DHCP handles IP address changes for some users, like the laptop owners. They need to connect and disconnect more often than a desktop PC. This is not a problem for the protocol.

• Scalability

As businesses and networks grow, DHCP scales effortlessly. Whether a network has tens or thousands of devices, DHCP can manage IP address allocation seamlessly. Therefore, it is essential for large enterprise networks or public Wi-Fi networks where a vast number of devices connect and disconnect constantly. Its scalability helps maintain an efficient network even as the number of devices expands.

Disadvantages of DHCP (security concerns)

The primary goal of DHCP was mainly focused on making an IP address assignment a quick and efficient task. That was successfully achieved, yet a compromise was also made with security and authentication.

The DHCP server doesn’t require authentication when providing a lease. That way, if there is not a firewall working, someone can get the data from the network. The majority of large enterprises have many authentication requirements for users in order for them to access their network resources. However, that is still not enough and leaves the DHCP server in a weak spot in the security chain.

Rogue DHCP server. If such a server gets connected to the network, it can start assigning IPs to the devices. These devices will share data with it, and their information can be seen by the server. It means that hackers can steal the data that way. There is a possibility a cybercriminal to spoof or take control of the DHCP server. Then, as a result, it can give out dangerous data to legitimate end users, directing them to a bogus website. In another scenario, unauthorized users can receive legitimate IP addresses, which is a prerequisite for man-in-the-middle attacks and Denial-of-Service (DoS) attacks.

Troubleshooting with DHCP

As with any technology, DHCP can sometimes run into issues. When your device can’t connect to a network, DHCP might be the culprit. Here are a few common problems and their solutions:

• IP address conflict: If two devices on the same network end up with the same IP address, they can’t communicate properly. To fix this, the conflicting devices need to be assigned different IP addresses.
• DHCP server unavailability: If the DHCP server goes down, devices won’t be able to get IP addresses. Ensuring server uptime and redundancy is essential.
• Lease expiry: If your device can’t connect, it might be because its DHCP lease expired. You can manually release and renew the lease to get a new IP address.

Conclusion

Now and then, there comes a technology that makes our lives easier. Maybe it is not so visible, and just a few people know that it exists, but the DHCP deserves our “thank you.”

It has its downsides, but the time it saves is far more valuable.

The post What is DHCP? How does the DHCP server work? appeared first on ClouDNS Blog.

Understanding DNS

The Domain Name System, or shortly DNS, is the internet’s address book, responsible for translating human-friendly domain names (like www.domain.net) into the numerical IP addresses (like 123.45.6.7) that computers use to communicate with each other. It acts as a distributed database, allowing quick and efficient DNS resolution of domain names to IP addresses (IPv4 and IPv6).

Additionally, DNS is a part of the application layer. As you probably know, all application layer protocols require the use of a transport layer protocol like UDP (User Datagram Protocol) and TCP (Transmission Control Protocol). In the case of DNS, it prefers to utilize the not-so-reliable UDP protocol in most cases. Yet, occasionally it uses the more reliable TCP protocol. 

Let’s dive deep and explain more about these protocols and when and why the Domain Name System puts them in use.

DNS using UDP and TCP

Both UDP and TCP are protocols used to send packets of data over the internet. They do that on top of the IP protocol, which means that they direct the packets to IP addresses. They are treated very similar on their way from the users’ computers, through the routers and all the way to the end destination.

DNS and TCP

TCP, also known as Transmission Control Protocol, is a widely used transport layer protocol. When you make a request for a website from your browser, it will most probably use exactly TCP protocol to send the data packets to the server. For every request you send (every action you take on the web page like click, sign in, etc.) you will receive TCP packets back.
TCP is orientated to the reliability. All the data sent over TCP is tracked, and no data gets corrupted or lost on the way. The protocol numbers the packets and does error checking by pushing the receiver to confirm that it got the data.

Here are some cases in which DNS utilizes TCP (Transmission Control Protocol):

• Zone Transfer: When a DNS server needs to transfer a complete DNS zone to another server, it typically uses TCP. This ensures the reliable delivery of larger data.
• Large DNS Responses: TCP is used when DNS responses exceed the maximum size supported by UDP, which is 65,535 bytes. This can happen with DNSSEC or large resource records.
• DNS over TCP (DoT) and DNS over TLS (DoT): For enhanced security, DNS can be encrypted using TCP-based protocols like DoT and DoT, protecting against malicious attempts.
• Firewall and Network Restrictions: When firewalls or network policies block UDP, DNS queries and responses are transmitted over TCP.

Learn more about TCP (Transmission Control Protocol) !

DNS and UDP

The UDP protocol is all about speed. All those checking of the packets slow down the communication and create latency. By using UDP, the receivers don’t need to confirm the packets; the sender just continues sending without wasting extra time to receive feedback. In this communication, the receivers lose some of the packets, but it doesn’t stop the communication. This makes it perfect for live streaming or online games, even if the connection stops for a bit and the screens of the receivers freeze, in a moment they will receive the next packet, and everything will continue.

DNS primarily uses UDP (User Datagram Protocol) for most of its operations. UDP is chosen for its speed, efficiency, and suitability for small, time-sensitive DNS queries and responses. UDP is used in the following cases:

• Regular DNS queries: When you enter a web address, UDP is used to send the query from your device to a DNS server.
• DNS responses: The DNS server sends the response, including the IP address, back to your device using UDP packets.
• Caching: DNS servers often cache previously resolved queries, allowing for faster responses using UDP without querying authoritative servers again.
• Small data transfers: DNS queries and responses are typically small, fitting well within UDP’s maximum packet size of 65,535 bytes.
• Stateless communication: DNS operates on a stateless model, and UDP’s stateless nature enables the efficient processing of multiple requests together.

UDP explained in details

Why does DNS prefer UDP?

As you just read, the UDP is unreliable but a lot faster than TCP, but don’t panic just yet. DNS requests are very tiny, so they have no problems fitting into the UDP segments.
It doesn’t use a time-consuming three-way hand-shake procedure to start the data transfer like TCP does. The UDP just transmits the data and saves plenty of time.
UDP can support many more clients at the same time thanks to the lack of connection state. The TCP has Receive and Send buffers, Sequence and Acknowledge Number Parameters and congestion-control parameters.
Don’t think it is so dangerous using UDP, you can add extra protection on the application layer. An application can use it and it can be reliable by using timeouts and resend at the application layer.

How does Domain Name System work?

In the DNS world, we are trying to cut the resolving time as much as possible. Seconds is an eternity, we want to reduce the time to just a few milliseconds. TCP is more secure, but it just can’t keep up with the UDP, and about protection, there are extra ways of adding it. So, in the end, you get them both – speed and protection.

Advantages and Disadvantages of Using UDP for DNS

UDP is widely used for DNS operations. Below are some of the advantages and disadvantages of using UDP for DNS.

Advantages:

• Speed and Efficiency: UDP is faster than TCP because it is connectionless, which means it does not establish a connection before sending data. This makes DNS queries quicker and more efficient, crucial for the large volume of DNS requests.
• Lower Overhead: UDP has less overhead compared to TCP, as it does not perform error-checking and connection management. This results in faster data transmission and lower latency.
• Simplicity: UDP has a simple protocol structure that allows easier and faster processing of DNS queries and responses.

Disadvantages:

• Lack of Reliability: UDP does not guarantee the delivery of packets, which can lead to packet loss. This lack of reliability can affect the accuracy of responses.
• No Error Correction: Since UDP does not include mechanisms for error correction, any lost or corrupted packets are not retransmitted. Additional mechanisms to handle these issues may be needed.
• Security Concerns: Because it is stateless, it is more exposed to spoofing and other types of attacks, requiring additional security measures.

Despite these challenges, the efficiency of UDP makes it a preferred choice in DNS operations. Its ability to quickly resolve numerous requests with minimal overhead outweighs the potential drawbacks, making it suitable for the high demands of DNS queries.

Conclusion

In conclusion, DNS uses UDP due to its speed, efficiency, and suitability for most DNS operations. UDP allows fast DNS resolution of domain names, quick delivery of DNS queries and responses, and efficient processing of small, time-sensitive data transfers. While TCP is employed in specific cases such as zone transfers, larger responses, and encrypted communication, UDP remains the preferred choice for its lightweight nature and low resource usage. The utilization of UDP in DNS ensures the smooth functioning of the internet, connecting users to their desired websites and services with speed and efficiency.

The post Why does DNS use UDP? appeared first on ClouDNS Blog.

What is FTP?

FTP, or File Transfer Protocol, is a standard network protocol used for transferring files between a client and a server. It dates back to the early days of the Internet and remains widely used today. It operates on the client-server model, where one computer (the client) establishes a connection with another computer (the server) to exchange files. FTP supports two modes: active mode and passive mode, which determine how data connections are established. It uses separate control and data channels, making it ideal for large file transfers, directory synchronization, and remote file management.

FTP is an old protocol, still from the age without a graphical interface. Abhay Bhushan first published it on 16.04.1971. You can access it through the command-line, or through a modern graphical interface. There are options that integrate it inside programs for web admins.
FTP transfer files by using the TCP. It needs to establish two connections, the data connection on port 20 and the second is control information on port 21.
You can use FTP if you are trying to install WordPress or another CMS on your web hosting. You can also use it to back up your website and download a copy of it to your computer. Less and less, people are using it to transfer files between them. The cloud solutions are making FTP absolute.

What is HTTP?

HTTP, or Hypertext Transfer Protocol, is the foundation of the World Wide Web. It defines how web browsers and web servers communicate and exchange information. HTTP functions through a request-response model, where a client sends a request to a server, and the server responds with the requested data. It operates on the application layer of the TCP/IP protocol suite, making it versatile for various web-related tasks, including browsing, data retrieval, and API interactions.

The creator of it is the famous father of the internet – Tim Berners-Lee. He developed it back in 1989 in CERN. Just like the FTP, HTTP also uses a client-server model. When you use your web browser and type an URL, you will use HTTP over TCP/IP (port 80). That way, you send a HTTP request to get the desired website (text, images, videos and all other kinds of content). The web server will give you back the answer with the desired web page (all files on it).

FTP vs HTTP

Both FTP and HTTP are part of the application layer that combines communication protocols and interface methods. Here we will see how they are different.

• You can use HTTP to view websites and the FTP just for transferring files.
• The client for HTTP is the browser (Chrome, Opera, etc.) and for the FTP is the command-line.
• Both can be used to admin a website, but HTTP is more popular. Just in some cases, the FTP can be more appropriate.
• It is believed that FTP is more efficient for larger files, while HTTP is better for smaller files.
• FTP doesn’t send meta-data, just binary and the HTTP uses pipelining to organize the transfer of multiple files.

Here is a comparison table that illustrates the differences between FTP and HTTP:

Suggested: SFTP vs HTTPS

Choosing the Right Protocol

The choice between FTP and HTTP largely depends on your specific requirements. Additionally, when deciding, it’s important to understand the specific advantages of each protocol.

FTP might be the optimal choice if your primary objective is to transfer files, especially large ones, access remote servers, or perform backups. It handles larger data sizes more efficiently and allows for the resume of transfers in case of interruption. It is ideal for situations like server migrations, backing up large databases, or transferring high volumes of media files.

On the other hand, HTTP is more suitable if you primarily engage in everyday web tasks such as web browsing, downloading smaller files, or interacting with web applications. HTTP is stateless by nature, making it efficient for these types of operations where each new connection doesn’t need knowledge of previous interactions. Additionally, HTTP’s ability to work seamlessly with modern web technologies and its compatibility with various data formats makes it the better choice for web-based applications.

In summary, choose FTP when dealing with extensive file transfers or when working within a network that you control for tasks like backups and server maintenance. Opt for HTTP when you need to interact with web pages or services, especially when performance and compatibility with web standards are critical. That way, you will ensure you leverage the strengths of each protocol based on your specific needs.

Conclusion

FTP vs HTTP is not really a question anymore. The internet has adopted the HTTP standard, and there is going back. FTP is not a bad protocol, but HTTP can do almost everything it can. And the safer version HTTPS is the new must on any page. FTP is starting to have problems with some firewalls because of the port that it is using (some firewalls allow just the ports for HTTP and HTTPS). FTP will soon disappear, and it is ok to let it go.

The post FTP vs HTTP: Understanding the Key Differences appeared first on ClouDNS Blog.

What is IP (Internet Protocol)?

IP is an abbreviation of the internet protocol. The IP is the way devices connect to the internet. It has a set of rules that define how the data travels from host to its destination. Basically, we need to define what we see (hostname), where it is (IP address), and how to get there (route).

To identify all the devices (hosts), there are IP addresses that are unique to them. They are assigned by the network administrators and could be static (fixed) IPs or dynamic (changing automatically after time) IPs.

An IP address is a simple string of numbers that are separated by periods. An example of an IP is 127.0.0.1, which is the localhost of most network systems.

First, the IP protocol was part of the TCP/IP. The first version that separated from it was the IPv4.

Types of IP addresses

When are talking about cosumers’ IP addresses, we can define four:

• Private IP addresses

The Private IP address is used inside the network. Imagine your home or office. You have a router that probably uses a dynamic method of IP allocation like DHCP. Your device will request an address, and it will receive one. This is a private IP address for the network that your router creates. Other devices (computers, IoT devices, phones) connected to the Internet thought this router would get their IPs the same way.

The router uses the addresses to identify the connected devices and manages those IPs to provide to other devices later.

Router vs firewall, can you guess which is better?

• Public IP addresses

Now we are going broader. Your router will get another IP address from your Internet service provider (ISP). This is a public IP address from the IPS’s pool of IP addresses for outside of your network recognition.

This public IP address can be a dynamic IP address leased to you by a DHCP or another type of server for a limited amount of time, or it could be a static IP address that will be fixed for you. The static could allow you to offer services that require such an IP address, but usually, it requires an extra payment.

DNS vs DHCP. Are they connected?

• Static IP addresses

For a certain set of devices, having a consistent IP address is of utmost importance. This is the case with static IP addresses, which are set and remain fixed over time. It is used mainly on networks where a device needs to be identified in order to access resources or services. Examples of static IP address are 192.168.1.100, 10.0.0.15 and 172.16.1.255. With a static IP address, a computer is always assigned the same address, which makes it easier to access remote resources.

• Dynamic IP addresses

For many networks, having a single dedicated address isn’t feasible as the amount of devices connected can fluctuate. It’s here where dynamic IP addressing comes into play. It is one that changes every time an individual device connects to a network. It is used on networks where a station needs a unique address for a limited time, after which a different device may use that same address. Dynamic IP addresses are not permanent, so the device connected to the network keeps changing IP addresses as needed. 

What is IPv4 address?

IPv4 address is the Internet Protocol version 4 address that serves to identify a device on a network and looks like this 157.240.20.35. It has 4 numbers that can be from 0 to 254, and are divided by dots.

The IPv4 started being used in 1982 on SATNET and one year later on ARPANET.

The IPv4 protocol allows interconnected networks and transmission of data from one place (source) to the destination. It passes datagrams from one internet module to the next until the destination is reached. If the data is too large to pass through a network, it can get fragmentation, chopped into pieces, and pass the limit of the network.

 Problems with IPv4

• A scarce number of available IPv4. The total number of available IPs is 4 294 967 296 (232). It looks massive, but think about how many connected devices are there. Yes, they are already more, and the internet service providers need to reuse their available IPs. Some are running out of numbers already, and they are starting to provide IPv6 addresses.
• Does not support IPsec natively. Yes, it could be configured, but it is harder.
• Limited IPv4 header (60 bytes). You can’t add any additional parameters.
• The price of IPv4 is rising. Each year the price is rising. Currently is above 25 USD. Maybe finally, the price will be the number one driver to move to the superior IPv6.

When we are talking about DNS and IPv4 addresses, we need to resolve the hostname to its IP address, and we use A records for that purpose.

If you want to check your domain’s A record, we recommend you take a look at the first command from our article: 10 Most used Dig commands

What is IPv6 address?

IPv6 is the latest version of IP. It has been around since 1995 and was introduced to replace the IPv4 back in 1998. Since 2017, the IETF (Internet Engineering Task Force) has ratified it as an Internet Standard.

In contrast to the IPv4, which uses 32-bit addresses, the newer version IPv6 uses 128bit addressing. To see the difference, we will start with one example of IPv6: “2001:0db8:0000:0042:0000:8a2e:0370:7334”. It has 8 groups, double the number of the previous. Each group has 4 hexadecimal (hex) digits, and the groups are separated by colons.

As you can see, there are many more combinations of available IP addresses. To be precise, 1028 times more available addresses!

Another benefit of the new protocol is the increased security. It has IPsec (Internet security protocol). It authenticates the sender (with Authentication Header) and encrypts the data (Encapsulating Security Payload).

Stateless address auto-configuration (SLAAC) is important too. The IPv6 auto-configures by listening to the Ruter Advertisement (RA), from the host. After that, it auto-assigns a 64-bit prefix. The other 64 bits of the address come from the host who self-determines its address.

The main problem of the protocol is the slow adoption from the ISPs (internet providers). They mostly prefer to use IPv4 because they don’t want to invest in new technology. Currently, the adoption rate is 41.35% (date 14.05.2023, oogle IPv6 adoption statistic ), and the leaders are France with 74.68%, second is India with 68.76%, Germany with 67.5%, Belgium with 67.25%, Greece with 61.29%, and the Saudi Arabia with 60.47%.

You can use IPv6 addresses on your managed DNS with AAAA records.

If you need more information you can look at our detailed article about IPv6.

Where is the IPv5 address?

Ok, there are almost no IPv4s left. Why aren’t we moving to IPv5? Why did we skip it? The reason is that IPv5 doesn’t exist. It never made it to become one of the IP protocols. It was planned as a streaming protocol, and it got to its second version, ST2. Its packets had the IP version 5 ID but eventually died as a draft. To evade confusion, the next protocol was named IPv6.

The big problem IPv5 had was that it used the same IPv4 addressing and had the same limited number of addresses.

Part of its development went to the next version, and that is how IPv5 history finished. But let’s see in more detail why IPv5 never came.

Why did IPv5 never emerge?

The journey of IPv5 towards becoming a mainstream internet protocol was halted by several key factors. Its development, closely tied to IPv4’s architectural framework, did not address the looming issue of IP address exhaustion that threatened the internet’s scalability. This critical shortfall, coupled with the emerging needs of a rapidly expanding digital world, necessitated a more comprehensive solution. Enter IPv6, with its vast address space and improved functionalities such as enhanced security and efficient routing. 

As the global internet community gravitated towards adopting IPv6 for its future-ready capabilities, IPv5 remained a crucial yet bypassed step in the evolution of internet protocols, serving as a testament to the ongoing pursuit of technological advancement.

IPv4 vs IPv6

So we are finally getting to the true IPv4 vs IPv6 comparison. Here we are going to put the attention on the fundamental differences that the two protocols have. You will see how much did the new one improve over the IPv4.

IPv4 vs. IPv6: Speed comparison

Is the new IPv6 faster than the previous IPv4?

• IPv6 has one big advantage: it does not need Network Address Translation (NAT). It uses global addresses because simply there are enough addresses, and it does not need the NAT, while IPv4 will have to deal with NAT.
• The older protocol has header checksums for bit errors because back when it was introduced, the connectivity was far worse. The newer does not, and its header is fixed to 40 bytes.

Currently, IPv6 is mostly faster than IPv4, with small exceptions.

IPv4 vs. IPv6: Security comparison

• As we mentioned before, IPv6 already includes IPSec. IPSec can be used with IPv4. Just it takes extra steps.
• Address scanning is a lot harder for IPv6. We are talking about a massive number of IPv6 subnet addresses. It will take an incredibly long time for an attacker if it does not use some extra criteria for its scanning.
• IPv6 can support end-to-end encryption. This can reduce man-in-the-middle attacks.
• Another feature of the new protocol is called SEND (Secure Neighbor Discovery). It is a cryptographic check of a host to see if it is truly the one that it says it is.

Benefits of the IPv6 summarized

• Better routing without fragmentation of packets
• Extended address space (128it vs 32bit)
• IPsec
• SLAAC – Stateless address auto-configuration
• An improved structure of the header with less processing overhead

What Internet Protocol version does ClouDNS use?

If you host your domain at ClouDNS, you might be wondering whether ClouDNS uses IPv4 or IPv6. ClouDNS currently uses both IPv4 and IPv6 addresses.

IPv4 enables compatibility with more older devices while IPv6 provides a larger address space, faster response time, and better support for quality of service. ClouDNS ensures the optimum operation of your website, application or any other service across multiple generations of devices and networks. This allows users to easily access your content no matter their device or network, securely and quickly.

Conclusion

IPv4 vs IPv6, now you know the difference. IPv6 provides enough IPs for a long, long time. We probably won’t see any new version any time soon.

As we stand today, more than 25 years from the beginning of IPv6, it is already used by 30% of the world’s Internet users. It will be the preferred IP version in the future, and it is important to start adopting it today.

The post IPv4 vs IPv6 and where did IPv5 go? appeared first on ClouDNS Blog.

Primary DNS server explained

The Primary DNS server is also known as Master server. It is responsible for hosting the zone file. This file contains information about the domain in forms of DNS records. Each domain can have just one Primary DNS server. You can manage the zone by those DNS records. You can add, edit or delete those records. The Primary also synchronizes its data with the rest of the servers if there are some. There are usually Secondary DNS servers who have a copy of the zone data. This helps with redundancy and guarantees more up time.

How does the Primary DNS server work?

The Primary DNS server is responsible for maintaining the authoritative copy of the DNS zone file for a particular domain. The DNS zone file contains information about the domain’s resource records, such as IP addresses, MX records, and NS records. 

When a recursive server receives a DNS query for a domain, it will search for the IP address associated with that domain. If the DNS resolver is configured to use the Primary DNS server for the domain, it will send the DNS query to that server. The Primary will then search its zone file to find the requested information and send it back to the DNS resolver, which will, in turn, return the information to the user.

The Primary is also responsible for updating the DNS zone file with any changes that occur to the DNS data. These changes can happen, for example, when creating a new DNS record or adding a new email server. Once the Primary DNS server updates the zone file, it notifies other DNS servers that it is authoritative for that domain, so they can update their own cache accordingly.

Is just a single Primary DNS server enough?

Yes, it is possible for a single Primary DNS server to be sufficient for a domain name, yet it poses a significant risk of a single point of failure. If the server experiences any issues such as maintenance, updates, power outages, or technical difficulties, there will be no backup to respond to DNS queries. Therefore, it is recommended to have a network of at least a few Secondary DNS servers that can share the load, reducing stress on the Primary DNS server and providing redundancy.

How to protect your Primary DNS?

There are different approaches for keeping your Primary DNS safe and protected.

First let’s think about the data flow. In every step, where there is a data transfer, there could be a potential threat.

1. The zone file. It can get corrupted by an accidental mistake or malicious activities. It should be secure, and you need to do a backup often. Also you will need an excellent administrator to handle it.
2. Dynamic updates. Here, significant threats are the unauthorized updates. You can limit only specific IP to be able to make such updates.
3. Zone transferring. Again, limit the IPs which can do it.
4. Remote queries. Better use a secure VPN for this kind of interaction or someone can intercept your remote queries.

The second excellent solution for guaranteeing the security and protection of your network is Secondary DNS. Once you implement it, you will have an additional set of Authoritative DNS servers for your domain name. That way, if your Primary DNS server fails and is not able to handle the incoming DNS requests for your domain, the Secondary DNS servers will handle the load, and your website or service will remain available for your clients. Secondary DNS is also known as Backup DNS due to the fact it makes a copy and stores all of the DNS data (DNS records) for your domain. So, it is a secure backup if you lose your original information.

How to use both Primary DNS and Secondary DNS?

You can use ClouDNS as your Primary DNS provider and use another company for Secondary DNS or vice versa. Just remember that you control the zone file through your Primary DNS, so better choose a provider that offers easy to use control panel and has excellent customer service.

Best Practices for Primary DNS Server Management

Let’s talk a little bit about the best practices when it comes to managing a Primary DNS server:

• Regular Backups: Performing regular backups of the Primary DNS Server’s configuration and zone files is essential. It safeguards against data loss. This practice ensures that, in the event of a server failure or other catastrophic events, administrators can quickly restore the DNS data to its previous state.
• Monitoring and Logging: Implementing comprehensive monitoring and logging tools helps administrators track the performance and health of the Primary DNS Server. Monitoring tools can provide insights into query volumes and response times and detect unusual or suspicious activities. The practice is crucial for identifying potential issues and mitigating security threats. 
• Redundancy and High Availability: To enhance reliability, administrators should configure Secondary DNS servers to provide redundancy. Secondary servers will still respond to DNS queries if the Primary DNS server becomes unavailable, which also helps minimize downtime.
• Security Measures: The security of the Primary DNS Server is paramount to prevent unauthorized access or tampering. Implementing secure practices, such as access controls, firewalls, and routine security audits, helps safeguard the integrity of the DNS records.
• Regular Updates and Patching: Keeping the DNS server software up-to-date with the latest patches and updates is crucial for handling security vulnerabilities and ensuring optimal performance. Regular updates also help incorporate new features and improvements.

Conclusion

In conclusion, the Primary DNS server is a crucial component of the DNS hierarchy, responsible for maintaining the authoritative copy of the DNS zone file for a particular domain. It plays a central role in DNS resolution, and keeping it safe and protected is essential.

The post What is a Primary DNS server and how does it work? appeared first on ClouDNS Blog.

What is IPAM?

IPAM – IP Address Management. It is a method of planning, tracking, and administrating the information related to IP address space. With IPAM software, a network administrator can manage the available IPs. This type of software can automate IP management, DNS, and DHCP configurations. 

A typical IPAM software can:

• Show you the available IPs at the moment.
• The status of the IPs – permanent or temporary.
• The hostname related to each IP address.
• Routers in use by each device.
• Show the subnets, who is using them and how large they are.

Why is IPAM important?

Effective IPAM is crucial for network stability and security. Without proper IP address management, networks can experience IP address conflicts, which can result in downtime, data loss, and other issues. It also helps to prevent unauthorized access to the network, which can lead to data breaches and other security risks. Additionally, IPAM enables efficient use of IP addresses, reducing costs associated with address management.

How does IPAM work?

IPAM (IP address management) provides a centralized way for tracking, assigning, and managing IP addresses on a particular network. That way, administrators can easily allocate IP addresses to devices, manage IP address assignments, and automate various network management tasks. Here are the main actions involved in IPAM:

1. IP address discovery: Typically, IPAM tools start by scanning the network to discover available IP addresses and identify devices currently connected to the network.
2. IP address allocation: Once it discovers the available IP addresses, IPAM administrators can allocate IP addresses to devices manually or automatically. This can be done based on predefined policies or rules.
3. DNS record management: IPAM tools can also be utilized to manage DNS (Domain Name System) records, which map domain names to IP addresses. If needed, DNS records can be created, modified, or deleted.
4. DHCP configuration: IPAM can also be used to configure DHCP (Dynamic Host Configuration Protocol) servers, which automatically assign IP addresses to devices on a network. DHCP configuration can be accomplished from the IPAM system. That reduces the need for manual DHCP configuration on individual devices.
5. IP address tracking and reporting: IPAM tools maintain a database of all IP addresses used on the network, which allows administrators to track IP address usage and quickly identify and resolve IP address conflicts. In addition, it can generate reports to show IP address usage statistics, history, and other relevant details.

Benefits

IPAM (IP Address Management) offers several benefits to organizations implementing it. Some of the key benefits are the following:

• Improved Network Stability: IPAM helps to prevent IP address conflicts, which can lead to network disruptions and downtime. By maintaining a precise list of IP addresses and automating IP address allocation, it can help ensure that IP addresses are assigned in a way that minimizes the risk of conflicts.
• Enhanced Network Security: IPAM allows organizations to monitor IP address usage and identify unauthorized devices on the network. That way, it helps prevent unauthorized access to the network and reduces the risk of data breaches and other security incidents.
• Reduced Costs: IPAM can help reduce operational costs associated with IP address management. By automating IP address allocation and DNS record management, IPAM tools can reduce the time and resources required to manage IP addresses.
• Efficient Use of IP Addresses: IPAM can help organizations make better use of available IP addresses by identifying unused or underutilized IP addresses and reallocating them as needed. This can help reduce the need for additional IP addresses, which can be expensive and time-consuming.
• Centralized Management: It provides a centralized way for IP address management, allowing administrators to manage IP addresses from a single location. It helps simplify the process and reduce the risk of manual errors.
• Scalability: IPAM tools are designed to be scalable, allowing organizations to manage IP addresses across multiple networks and locations. This is especially beneficial for larger organizations that have complex network environments.

Working without IPAM

Yes, it is possible to live without IPAM, but it is harder. The IT staff can manage a small network with a spreadsheet. In it, there can be a table of IPs, connected devices, routers, and port numbers. The problem starts when the network gets bigger. The admin will have to check far many IPs and continuously update the spreadsheet.

Several obvious problems could arise:

• IP address conflict. If there is no DHCP well-configured, and the admin is doing it manually, IP conflict could happen. If two devices get the same IP, none will be able to connect. This could be particularly annoying if one of the devices is a server, and it can lead to a massive outage.
• Security problems. There is a high-probability of security breaches. The accountability is weak, and a new device could connect to the network.
• Compliant issues. Depending on which country you are in, having logs and reports for your IP address space might be required. You will need to provide a proper report.
• Troubleshooting problems. Manually, everything is harder. Finding the exact network problem might be a nightmare. Is it the port, IP conflict, or something else? It can take ages.

IPAM Integration with DNS and DHCP

The integration of IP Address Management (IPAM) with Domain Name System (DNS) and Dynamic Host Configuration Protocol (DHCP) is a significant step forward in network management. This integration simplifies the process of assigning, tracking, and managing IP addresses within a network environment.

• IPAM and DNS: By harmonizing IPAM with DNS, the system ensures accurate mapping between IP addresses and domain names. This synchronization is vital for efficient network functioning because it allows for quick and reliable resolution of domain names to their corresponding IP addresses. This helps devices and services to communicate seamlessly with each other.
• IPAM and DHCP: When IP address management (IPAM) is integrated with Dynamic Host Configuration Protocol (DHCP), it optimizes the dynamic allocation of IP addresses to devices. With this automation, administrators reduce their manual work and lower the risk of potential IP conflicts. It also ensures that IP resources are used efficiently. With IPAM and DHCP working together, you can have centralized control and real-time monitoring of IP address assignments, which leads to better network management and security.

The proper integration of IPAM with DNS and DHCP, combined together into a solution known as DDI, can empower administrators with comprehensive visibility and control over IP address allocation, DNS resolution, and DHCP configuration.

Open-source IPAM Software

There are plenty of IPAM software out there, but if you have a small or medium-size business a free open-sourced IPAM can be the right choice. All of these options support IPv6 and VRF (virtual routing and forwarding).

NetBox – It works with PostgreSQL database, under Apache license.

GestióIP – It has a web-based interface, advanced search options and uses MySQL under GPLv3 license.

phpIPAM – Another good free option with many features. phpIPAM uses MySQL and MariaDB under GPLv3 license.

These 3 options will get you started with IPAM. Later, if they don’t all of your needs, you can check paid software too.

Best Practices

Here are the best practices for effective IP Address Management (IPAM):

• Invest in Updated Tools: Use tools that regularly update and audit IP address records to maintain accuracy and efficiency in management.
• Integration with Network Tools: Integrate IPAM solutions with other network management tools for a unified network overview and faster troubleshooting.
• Access Control and Permissions: Restrict access to network controls to only necessary personnel to enhance security.
• IP Subnetting: Implementing IP subnetting to break down large networks into smaller subnets is another way to make IP address management more effective.
• Critical in IPv4 to IPv6 Transition: IPAM plays a crucial role during the switch from IPv4 to IPv6. Choosing and implementing the right IPAM solutions can significantly ease the transition.

Conclusion

IPAM is an excellent way of removing network burden from your IT staff. It will make the network administration far easier and organized. Applying IPAM in your company can improve productivity and reduce network problems. 

The post What is IPAM? Can you work without it? appeared first on ClouDNS Blog.

What is IPsec?

IPsec is a set of protocols to secure internet communication at the network layer. It was developed by the Internet Engineering Task Force (IETF) to provide a secure way to exchange data over the Internet, ensuring that sensitive information is protected from unauthorized access, interception, or modification.

IPsec is the short acronym for Internet Protocol Security. The “IP” stands for Internet Protocol, which is the main routing protocol used on the Internet for sending data to its destination using IP addresses. The “sec” stands for secure, as it provides encryption and authentication to the data transmission process, making it more secure.

Its main goal is to encrypt data, provide authentication and access control, and ensure the integrity of the data being transferred. It helps many organizations protect their data from malicious actors and ensure secure communication between devices. It is widely used for securing Virtual Private Networks (VPNs), providing a safe connection for remote access. IPsec also controls access, ensuring only authorized users can access the data or network. Additionally, it provides authentication, ensuring the data comes from a legitimate source. IPsec is a vital tool for organizations to protect their data and ensure secure communication.

Tracing its roots and evolution

The inception of IPsec can be traced back to the early 1990s, a time when the Internet was rapidly expanding, and the need for secure communication was becoming increasingly evident. Developed by the Internet Engineering Task Force (IETF), IPsec was designed to secure and encrypt data at the IP layer. Over the years, IPsec has evolved, adapting to the changing landscape of digital security.

In its early stages, IPsec primarily focused on securing communication between networks. However, as the Internet grew and new threats emerged, IPsec adapted to provide more robust and versatile security solutions. Key developments included the introduction of new encryption algorithms and improved key management protocols, enhancing its ability to safeguard data against increasingly sophisticated cyber threats. This evolution has established IPsec as a standard for secure Internet communication, trusted by organizations worldwide for its reliability and robustness.

What is IPsec used for?

It is commonly used to establish secure connections between networks, remote users, or individual devices over the Internet. IPsec works by encrypting and authenticating the data transmitted over a network, providing confidentiality, integrity, and authentication. This ensures that sensitive information such as passwords, credit card numbers, and personal data are protected from unauthorized access, interception, or modification. IPsec is widely used in virtual private networks (VPNs), which allow remote workers to securely access a company’s internal network from outside the office. It is also used in secure email, voice-over-IP (VoIP), and other internet-based applications that require safe communication. Overall, IPsec is an essential tool for ensuring the privacy and security of internet communications.

How does IPsec work?

To establish a secure connection, IPsec follows a set of several steps, which are the following:

• Key exchange: Keys are essential to enable encryption. A key is a sequence of random characters used to encrypt (lock) and decrypt (unlock) messages. IPsec sets up keys with a key exchange between the connected devices. That way, every device is able to decrypt the other device’s messages.
• Packet headers and trailers: When data is transmitted over a network, it is divided into smaller units known as packets. These packets include two main components: the payload, which is the actual data being transmitted, and the headers, which provide information about the data to allow the receiving computers to process it correctly. In the context of IPsec, additional headers are added to each packet to incorporate authentication and encryption information. Moreover, it also attaches trailers to the end of each packet’s payload rather than at the beginning.
• Authentication: IPsec provides authentication for every packet. This mechanism guarantees that the packets originate from a reliable source rather than a malicious attacker.
• Encryption: It provides encryption both for the payloads and the IP headers of each packet. This ensures that data transmitted over IPsec is protected and kept confidential.
• Transmission: The encrypted IPsec packets travel across different networks to reach their target destination using the UDP transport protocol. That is a significant difference compared to regular IP traffic, which typically uses TCP (Transmission Control Protocol), which sets dedicated connections between devices. On the other hand, UDP doesn’t set such connections, which allows IPsec packets to get through firewalls.
• Decryption: At the end of the communication, the packets are decrypted, allowing applications such as web browsers to access and utilize the data.

IPsec protocols

IPsec uses a variety of protocols to establish secure connections and protect data during transmission. IPsec is not one protocol but a suite of protocols. The suite includes the following:

• Authentication Header (AH): It provides data integrity and authentication and ensures that the transmitted data has not been modified or tampered with. Yet, it does not encrypt data.
• Encapsulating Security Protocol (ESP): It encrypts both the IP header and the payload of each packet unless transport mode is used, in which case only the payload is encrypted. In addition, ESP adds its own header and a trailer to each data packet.
• Security Association (SA): An SA is a set of security parameters defining how two devices communicate securely. It includes information such as the encryption algorithm, authentication method, and key size. One of the most commonly used SA protocols is the Internet Key Exchange (IKE).

IPsec Modes

IPsec offers two distinct modes that provide different amounts of protection for network communication.

• Tunnel Mode: In this mode, all data, including the header and payload, is encrypted, and a new header is added. It is ideal for secure data transfer over public networks, as it provides enhanced protection against unauthorized access. 
• Transport Mode: It encrypts only the payload while the IP header remains unchanged. The unencrypted header allows routers to identify the destination address of each packet, making it suitable for use in a trusted and closed network.

Benefits 

IPsec offers a number of benefits, including the following:  

• Data Encryption

With IPsec, all the data transmitted over the Internet is encrypted, making it impossible for cybercriminals to intercept and read it. The privacy of the data is especially important for businesses dealing with sensitive information, such as financial or personal details. 

• Authentication

It provides authentication, ensuring the communication between two endpoints is legitimate. That way, it prevents unauthorized access to the network and protects the network from various cyber-attacks. IPsec uses authentication methods to verify the identity of the users and devices on the network.

• Integrity

With IPsec, the data transmitted over the Internet is not tampered with or modified in any way. As a result, it ensures that the data received at the other end is the same as the transmitted data and that there has been no unauthorized alteration or modification.

• Compatibility

IPsec is a widely used protocol and is supported by many devices and operating systems. That signifies that businesses can use it to secure their networks without having to worry about compatibility issues.

Which port does IPsec use?

IPsec uses port 500 for its IKE (Internet Key Exchange) protocol. This port is used for the initial negotiation between two systems and to establish a secure connection. Once the connection is established, IPsec will then use a variety of other ports to send and receive data. These ports are usually randomly chosen and can range from port 4500 to port 5500.

It also uses port 4500, which allows IPsec traffic to pass through a NAT (Network Address Translation) device. This is important for allowing IPsec traffic to pass through firewalls and other security devices.

What is IPsec VPN?

An IPsec VPN is a network architecture that employs the Internet Protocol Security (IPsec) protocol suite to establish secure and encrypted communication channels over potentially unsecured networks such as the internet. This technology is designed to protect data integrity, ensure confidentiality, and authenticate data sources.

Technically, an IPsec VPN functions by encapsulating data packets and encrypting the payload with robust encryption algorithms. This process transforms the data into unreadable formats for anyone intercepting the packets. It employs two primary modes: Tunnel mode and Transport mode.

Furthermore, IPsec VPN uses sophisticated key exchange mechanisms, like IKE (Internet Key Exchange), to securely establish cryptographic keys between communicating parties. With its comprehensive approach to security, an IPsec VPN is essential for enterprises and individuals who require secure communication over the internet, especially for sensitive data transmission.

Conclusion

IPsec is the superhero of internet security! It’s an essential tool for businesses dealing with sensitive information and offers benefits like authentication, integrity, and data encryption. Implementing IPsec helps keep your internet communication safe and secure!

The post IPsec Explained: What It Is and How It Works appeared first on ClouDNS Blog.