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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User Datagram Protocol

Today we will explore the User Datagram Protocol. First, we will explain its purpose, and then we will see its history and how it was created. Finally, we will explore its applications and the differences between UDP and TCP/IP.

The purpose of the User Datagram Protocol 

UDP stands for User Datagram Protocol. It is a key component of the Internet protocol suite. It allows us to link various Internet services with minimal latency and loss tolerance.

The User Datagram Protocol speeds up communication by allowing data to be delivered before the recipient agrees. As a result, for time-sensitive communications such as DNS lookups, Voice over IP (VoIP), video, or audio transfers, User Datagram Protocol is the preferable technique.

Advantages and Disadvantages of UDP

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DNS CAA record

The DNS CAA record was first defined in 2013, and from September 2017, Certificate Authorities are obliged to review it before issuing any certificate. So, let’s clarify things a little bit more about it.

DNS CAA record – Definition

The CAA (Certification Authority Authorization) record is a Resource Record in DNS (Domain Name System) that lets domain owners to specify which CAs are authorized to issue a certificate for the domain name. 

Certification Authorities (CAs) are organizations that are authorized and able to issue certificates for domain names, for instance, SSL, TLS, or other certificates.

How to create a CAA record?

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IPv6

IPv6 is the most recent edition of the Internet Protocol, intended to replace IPv4. The Internet Protocol version 4 scarcity is a significant problem, but the world continues to move forward, so it’s time to let it go. The final IPv4 countdown has begun. Let’s look at what IPv6 has to offer and how to make the most of it!

IPv6 – what does it mean?

IPv6 is the sixth iteration of the Internet Protocol’s IP address. IPs are a set of rules that a device must follow when sending and receiving data from a host to a destination. We’ll need a list of recognizable hosts, their locations, IP addresses, and a communication path.

Returning to IPv6, it has been around since 1995! The strange thing is that there has been a scarcity of IPv4 addresses, as well as other issues. Despite this, the majority of organizations continue to use the earlier IPv4 standard. Since 2017, it has been an Internet Standard (IETF) to anticipate an increase in IPv6 usage in the near future.

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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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