Year: 2021

DKIM record

DKIM record explained.

Domain Keys Identified Mail for short DKIM record is a DNS record (TXT record) that is utilized to prove that the emails sent from the particular domain name are legitimate via cryptographic authentication.

The recipient, on the other hand, is also going to use the DKIM record when making the DNS query to the domain name for validating the sender. It is going to use the information in the header of the message.

The DKIM record includes the public key, which the recipient needs to confirm the message.

Once you wing an email with DKIM, you are going to attach a DKIM signature header and encrypt it. Then, the server sending the email signs the emails with its private key. After that, the recipients are going to unlock them with the public key. This process ensures that the messages are not going to be spoofed on the route. Additionally, they prove that they can be trusted.

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ALIAS record

We are going to explore one alternative to the CNAME record, which has many advantages – the ALIAS record. With it, you can have different DNS records in the same DNS zone and even put ALIAS records inside the root. Put ALIAS records where you can’t do it with CNAME records and manage your DNS easier. 

ALIAS record

The ALIAS record is one of the DNS record types which serves to connect one hostname to another. After that, it will resolve to A or AAAA record (an A to IPv4 address and an AAAA to IPv6 address) that already exists for the second hostname. ALIAS has the benefit of being allowed for the root domain, and you can put it in a DNS zone with other DNS records like MX records.

Benefits of using ALIAS DNS record

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TCP/IP

TCP/IP means Transmission Control Protocol/Internet Protocol. Originally, the two protocols with their set of rules got merged and used for machines to communicate on networks, including the Internet.

What is TCP/IP used for?

TCP/IP defines the way data is communicated on the Internet through end-to-end communications for deciding how such data must be divided into packets, addressed, routed, transferred, and received. 

DNS using UDP and TCP

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TTL

Let me tell you a funny story that will show you the importance of TTL when sending packages. 

Back in the day, in 1971, there was a programmer called Bob Thomas who was working on mainframe computers. He got bored and decided to play around. After a while, Bob created a small software called the Creeper and released it on the network. It was a tiny code with the message “I’m the creeper: catch me if you can”. Ray Tomlinson, a colleague of his, added the functionality and allowed the code to copy itself. This was the first computer virus. The virus was unstoppable because there was no antivirus at this time, and it had no TTL, so it could go around the network forever. The co-creator Ray needed to invent the first antivirus to stop it. Otherwise, it could still go around for a long time. 

So what is TTL in networking? 

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SSL certificate

Internet’s creation brought to the table a lot of possibilities but also a strong need for security. The development of all kinds of solutions for keeping businesses operating safely is a clear priority. In that environment, the SSL certificate plays an important role.

What is a SSL certificate?

SSL means secure socket layer. SSL certificate is a useful cryptographic protocol to protect the communication browsers-servers of websites. It helps browsers to verify servers’ identity, and it protects all data passing between them through encryption.

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DHCP

The DHCP is a perfect example of how technology can facilitate our lives, both as clients and network administrators. It is an IP manager that automatically allocates addresses to the connected devices, keeps the information about them, and reuses the IPs after they run out.

What is DHCP?

DHCP stands for Dynamic Host Configuration Protocol. It is a network protocol for managing IP networks that has a version for IPv4 and IPv6. The protocol defines DHCP client and DHCP server. The server is responsible for assigning IP addresses to the DHCP clients automatically and also keeping a record of the assigned IP addresses and their time to expire. It also provides other network settings like DNS server, gateway, subnet mask, and more.

Advantages of DHCP

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IPv4

You will learn what IPv4 is, how an IPv4 address looks like, and what is next after IPv4, IPv6.

What is IPv4?

IPv4 is one, a bit older Internet Protocol that has been around since the early 80s. The 4th version was introduced in 1981 and got in use since 1982. Been an Internet Protocol (IP), its purpose is to establish all the rules for communication. How the data packets should be sent, what should happen with them, how to be received, and so on.

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Domain flipping

This is a beginner’s guide to domain flipping. Here we will show you your first move from buying a domain name to selling it for a profit.

Domain flipping in a brief

Domain flipping is the practice of buying domain names that have potential and reselling them later for a profit. The domains can be cheap with interesting names, or they can be expensive. The goal is to find interesting available domain names, and later to be able to find a potential buyer who is willing to spend the price you want.

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Ping command

Computer networking has lots of tools. From the most simple to the most complex, all have interesting functionality that sooner or later can be useful for you. 

What’s the Ping command?

Ping command is a software utility for testing if the connectivity is working between two systems. In other words, the reachability of a host on a network.

Utility software is the one created for configuring, analyzing, maintaining, or optimizing machines. It supports computers’ infrastructure. Ping command is a very popular resource for diagnosis, and it’s available (built-in) on all operating systems.

Ping command syntax for Linux

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