Round – Robin DNS meaning

After its launching in the 90s, load balancing becomes a game-changer in traffic distribution across networks. Round-Robin as a load balancer is significant in maintaining the flow of data moving efficiently and easily among servers and endpoints. It is also one of the most common and affordable techniques. Let’s explain a little bit more about it.

How does load balancing work?

Load balancing is a method for distributing traffic across networks. It is managing the different servers such networks include. Mainly the traffic in large networks has to be led to increasing the efficient general performance. Otherwise, you risk having weak sports in some points.

Few servers can get flooded with high traffic, and others at the same time could barely operate. This causes an incredible mess. Security threats like DDoS attacks will become less detectable and a lot more harmful.

Whit the load balancing method, you can administrate the traffic and optimize the network’s performance. The process is strongly recommended. A few more of its benefits are also faster loading time and a backup in case of an interruption.

Round – Robin DNS definition

Round-Robin DNS is a DNS load balancing technique that administrates the traffic. It depends on when a user request arrives and the number of servers you have. The concept is simple: you have various A or AAAA records that have different IP addresses. With every one of these IP addresses corresponds to a different web server. They have a duplicate of your site. When a user desires to reach your site, its browser tries to resolve your domain name. Your authoritative name server, which is responsible for the A or AAAA records, will give the next in rotation turn A or AAAA records from those you own. It is possible to have records for every one of your web servers. The visitors will be automatically redirected, when they are trying to access your site. This happens in order of the moment when they reached your DNS name server.

Let’s explain it a little bit more. 

Think a situation where you have 5 users and 3 servers:

User 1 attaches to server 1, user 2 to server 2, user 3 to server 3.

When user 4 wants to connect with the website, the circle will start again. User 4 will connect to server 1, user 5 to server 2, etc. 

DNS Round-Robin will reduce and administrate better the traffic to your site. As a result of Round-Robin, your customers will have a better user experience every time they visit your site. Also, a less saturated network and overall better performance.

The mechanism can be modified. If your web servers are not exactly the same. Let’s assume server 1 is a lot better than the other 2. It is a good idea to use it two times more. Like so, you get the best productivity. Here you could think for the Weighted Round Robin. 

Variants to the Round‑Robin algorithm

  • Weighted Round-Robin – The site administrator chooses criteria and assigns to each server the weight. The most regularly used criterion is the server’s traffic‑handling capability. The higher the weight, the more significant the proportion of user requests the server receives. 
  • Dynamic Round-Robin – A weight is allocated to every one of the servers dynamically. It is based on real‑time data about any of the servers’ load at the moment and unused potential.

TTL (Time To Live) explained

We live in an environment where time is probably one of the most critical factors in our everyday life. Computing and networking are not any different. Many of the processes frequently must happen in a specific period of time. Here comes TTL in hand. In some cases, the task should be finished in milliseconds. Can you imagine that? Let’s make things a little bit more precise and explain what TTL actually is?

What is TTL?

TTL is the short acronym for time-to-live. It refers to the value that points to the exact period of time or number of hops that the data packet is configured to be alive on a network. In some cases, also in the cache memory. When that time expires, or it hops the number of times, routers will discard it. There exist many different varieties of data chunks. Every and each of them operates with their particular TTL. That means the time such data will be held in a device to function or finish a certain task.

How does it work?

If the massive amount of packets is not controlled, they will travel around routers permanently. The way to avoid this is with a limit of time or expiration on every data packet. This allows understanding how long they have been around and track their route on the Internet.

Packets travel through network points with the purpose of reaching their final destination. There is a spot inside the data packets’ design where the TTL value is placed.

Routers receive the TTL value inside the packet. It will pass to the next network point if there is spare time or hops. But if the value of TTL shows that there is no more remaining hops/time, routers won’t pass it anymore.

Instead, routers will send an ICMP (Internet Control Message Protocol) message. This type of message is used to report IP errors or diagnoses and directs to the IP address source, which issued the packet.

It will take a specific time for every ICMP message to arrive at the source. During that time, it is likely to track the hops it made while alive on the network.

TTL and DNS 

TTL in DNS finds its place for the time that the DNS resolvers have to keep the DNS records in their cache. Every DNS record has its assigned TTL value. When it is of the record is longer, there is less chance that the value will change. Therefore other records with a lot and often changes will be with a shorter value.

And because DNS requests are also packets of data, they have their TTL value inside. It would be a very interesting case if they didn’t have such limitations. DNS queries would constantly go from server to server and never finding a destination. TTL value acts as a stop mechanism of a DNS request and prevents endless search for an answer and pointless stress on the Domain Name System. The value begins with a larger number and gets decreased until it comes to zero by the routers.

How does TCP work?

TCP definition

Transmission Control Protocol (TCP) is a communication standard that software applications are using for exchanging data. It’s planed for efficiency, not speed. Data packets, in data transport, sometimes get lost or arrive out of order. TCP helps to guarantee every packet reaches its destination and if it’s needed to be rearranged. If a packet doesn’t reach its’ end in a certain timeframe, TCP will request re-transmission of the lost data. It manages the connection between the two applications. This happens during the entire exchange. The goal is to ensure that both parties send and receive everything wanted to be transmitted and verify that it is accurate. TCP is a prevalent protocol in network communications. 

How does it work?

Transmission Control Protocol works through a process that includes several steps. 

As mentioned earlier, TCP is connection-oriented. It has to ensure that the connection between source and destination is set and endured until the sending and receiving of messages is performed.

The first step. TCP arranges the connection required by a source and its goal. During this stage, there’s a connection, but there’s not data transmission yet. 

The second step. Here communication begins. TCP receives messages from the sender (server or application) and divided them into packets. 

Third step. TCP adjusts the chopped data with numbers to regulate all the packets and protect messages’ genuineness. 

Step Four. Now chopped and numbered, messages will proceed to the IP layer for transporting. They will be sent and re-sent by the many devices connected in the network (gateways, routers, etc.) till they arrive at their destination. All packets can travel following a diverse route, but they all have the same end destination. 

Step Five. At the moment they arrive, they start rebuilding. By the numbers accredited to every message’s packet, it arranges all packets together again. 

Step Six. When messages are formed, they are transferred to their recipient. 

When networks’ performance is affected, TCP can help. For example, affected packets, which got duplicated, disordered, or lost. The protocol can recognize the specific problem, request the lost data to be transmitted again, and reorganize the misplaced packets in the proper order.

The source gets informed about a failure, if messages still don’t get delivered.

Transmission Control Protocol is a solid standard and definitely a solution for the Internet to operate better and more precisely. 

What is TCP used for?

TCP is a primary component of daily Internet usage. When you’re browsing the web and opening a web page, the webserver uses the help of HyperText Transfer Protocol (HTTP) to transfer the file for the website to your device. HTTP depends on TCP to connect the server to your computer and secure that the file gets carried correctly over IP. For example, Simple Mail Transfer Protocol (SMTP) for sending and receiving email, File Transfer Protocol (FTP) for peer-to-peer file sharing, also rely on TCP. 

When the correctness of the information transfer is more important than the speed, it is likely TCP to be in hand. It uses three-way handshakes to build the connection. It chops data to tinier packets and asks for re-transmission to secure accuracy. 

That extends the time for the data to transport from one application to another.

This prolonged latency restrains Internet usage. For example, Voice Over Internet Protocol (VoIP), video gaming, and video streaming can’t benefit TCP. In these cases, high-level protocols will use the User Datagram Protocol, which is faster but less precise.