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FTP (File Transfer Protocol)

​What is FTP (File Transfer Protocol)?

​FTP (File Transfer Protocol) definition

FTP (File Transfer Protocol) is a communication protocol designed for file transfer between a client and a server. FTP is a standard Internet protocol and uses TCP/IP for transferring the file from one device to another. It was created in 1971 (RFC 114) by Abhay Bhushan. Later it was updated in 1980, adding the TCP/IP compatibility. Finally, and some years later, in 1985, we got to the current version.

With the time IPv6 support was added, and so was added security extension for FTP. 

FTP was used straight off the Command Prompt or Terminal in the past since there was no graphic user interface (GUI). Now, there are FTP server applications and FTP client applications, both for computers and mobile devices, that provide a GUI.

​Advantages of FTP

  • You can use FTP for transferring large files. 
  • You can send multiple directories with files at the same time and speed up the transfer process. 
  • You can resume an interrupted FTP communication. 
  • Schedule transfers are available. 

​When to use FTP?

  • You can use FTP to download large files over the Internet.
  • Get a backup of your website.
  • Upload a large file to your web hosting.

It used to be far more popular in the past, but now it is still used to download different files over the Internet.

​The 2 FTP transfer modes

There are two modes that FTP has – active mode and passive mode. Both modes start the same. The client will use TCP to establish a connection from a random port to the FTP port 21 of the FTP server.

  • Active mode. The FTP client will be listening for incoming data connections that are coming from the FTP server on port M. The client will send the FTP command PORT M to show to the server that it is listening. When the server gets this feedback, it will establish a channel with the client on port 20 (FTP data port).
  • Passive mode. Due to a restriction, like a firewall stopping incoming connection to the server, there is a passive mode too. The client will use a control connection, and it will send the PASV command to the server. The server will respond with its IP address and port number. Then, using the data, the client will open a data connection from a random port to the IP address and port of the server.

​FTP security.

FTP is not a very secure way of communication. For example, it is possible to spoof the communication, capture the data packets, perform port stealing, make a brute force attack, and so on.

The original FTP does not use any encryption method. So the data packets, if stolen, could be read without any problems, and the data could be in a great risk.

FTP uses an username and password, but it is not enough to ensure security.

To improve the protection of the files that you want to send, you can use one of the following variations of FTP – SFTP (SSH File Transfer Protocol) or FTPS (File Transfer Protocol Secure).

  • SFTP uses SSH and requires only one connection. Not two (control and data) like in FTP. It provides encryption.
  • FTPS uses a SSL/TLS for the encryption of the data. It adds the SSL/TLS in addition to the username and password. It is more similar to the FTP and uses the two channels – data and control.

​Conclusion

FTP is a well-known protocol for file exchange. It is not a perfect protocol, but there are ways to make it more secure and use it.

DNS MX record

What is a DNS MX record?

The DNS MX record is one of the most used DNS records out there. Without it, you simply can’t be sure that you will receive any emails! You need the DNS MX record to signalize to the rest of the servers on the Internet, which exactly is your mail server responsible for receiving emails for the particular domain.

What is a DNS MX record?

The DNS MX record (Mail Exchanger) is a DNS resource record that identifies the host with its hostname and is responsible for receiving incoming emails for the particular domain name. It makes that connection between the domain name and the incoming mail server.

If you have yourdomain.com, you can set the MX record with the following parameters:

  • Host: yourdomain.com – your domain name.
  • Points to: mail.yourdomain.com – hostname of your receiving email server
  • Priority: 10 – the priority value could be from 0 to 100, where a smaller number indicates that it has a higher priority.
  • TTL: Time to live value.

How to create a DNS MX record?

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ALIAS record

ALIAS record: Why do you need it?

ALIAS record is one of the not-so-popular DNS records, but it is also very interesting. So let’s explain a little bit more about it.

ALIAS record explained.

The ALIAS record is a DNS record, which helps with linking two hostnames. Simply it is explaining that one of the hostnames is just another way to write the other one. This DNS record is not one of the standard ones, and actually, not every Managed DNS provider is offering it. The main benefit that comes with applying this record is that it can coexist with other DNS records, such as MX record. For example, the CNAME record is not able to do the same. Another amazing thing about it is that it will take a lot less time and present the other hostname and IP address.

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DNS propagation

DNS propagation – meaning

DNS propagation is a part of the challenging game, which the Internet is. When you are managing a network or a website, it will require regular changes to your strategy. Developing a more efficient, visible, competitive experience is the common reason for the change. For this to happen, administrators have to perform DNS modifications.

What is DNS propagation?

DNS propagation is the process of updating and spreading all of the new modifications you make in the Domain Name System (DNS). And that is all over the network. 

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Dig command

How to use the Dig command?

What does the Dig command mean?

Domain Information Groper is the abbreviation in the DIG command. It is a software that has the purpose of getting information about a domain. It can help you with detecting a problem with your domain. Simply by performing different DNS probing. You can see an individual DNS record or check a name server. 

How to use it?

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TTL

TTL meaning and definition

Time is a critical factor to be considered almost for everything. Every project, business, process, fixing, etc., you try is marked by a specific time. Computing and networking are not exceptions. Lots of processes must happen in determined periods of time, actually in milliseconds, to be considered efficient and successful. 

TTL meaning and definition

The letters TTL are the initials for time-to-live. It is the value that points to the exact period of time or number of hops that data packet is configured to be alive on a network or in the cache memory. Once that time expires, or it hops the number of times, routers will discard it. There are different kinds of data-chunks, and they all work with their specific TTL. Meaning, the time such data will be held in a device to complete determined tasks or functions.  

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DNS AAAA record

AAAA record explained

Domain Name System (DNS) is very important for the Internet to be as simple and friendly as it is right now. DNS is a game where different players have a position to cover for everything to work smoothly. DNS records are among those players. They play a key role in making domain names accessible. Without DNS records like AAAA, the DNS resolution could not be possible. In other words, the process in which domain names are linked to their corresponding IP addresses.

What is an AAAA record?

AAAA record is a DNS resource record. Whenever a domain name is requested, this record has to link such a domain name with its corresponding IP address in order for the site to be served and accessed. 

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Host command

Host command explained

What is Host command?

The Host command is a tool with a command-line interface for Domain Name System lookups. You can use it straight from the Terminal application since it is usually pre-installed on Linux-based and Unix-based OSes. You can use it on Ubuntu, CentOS, macOS, or others, without any difference in syntax or functionality?

Who created the command?

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DMARC record

DMARC record explained

What is DMARC?

DMARC is an abbreviation of Domain-based Message Authentication Reporting and Conformance, and it is a mechanism for secure email exchange that uses both SPF and DKIM. Having set up DMARC properly for your domain will reduce email phishing (thanks to the reporting of SPF) and spoofing (thanks to the encryption of DKIM). You will have a lot higher email sent success rate, and fewer emails of yours will end up in the spam folder.

Using DMARC will allow you to add an extra level of security on top of the SPF and DKIM.

You can set it up stronger, and even if SPF and DKIM pass, the DMARC still fails because of criteria.

You can make it lighter and limit the use to only SPF or only DKIM.

Why use it?

  1. To send emails uninterrupted. The emails will be encrypted, and the receiver will be able to unlock them with the public key. The presence of DMARC will indicate that the domain could be trusted.
  2. To stop others from using your domain name for phishing attacks. DMARC has the power to tell to the receiving servers – the domain is related to those particular servers. Anything different should be discarded immediately. It can work with allowing only good emails or stopping all bad emails, or both.

How to create a DNS DMARC record?

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IPAM IP Address Management

What is IPAM (IP Address Management)?

Do you remember when the Internet meant a connection to a desktop computer? Later laptops came to your business, followed by tablets, printers, and all your colleagues’ smartphones, etc. Have you considered how many devices are looking for Internet connection in your business facilities right now?

And this happens daily all around the world. The number of devices grows in such a way that managing networks are getting very complex. Just IP addresses’ assignation or tracking can take a lot of time. And network administrators have so many more tasks to comply with.

To do this manually is not really a choice. In such a scenario, IP address management (IPAM) is very convenient for you.

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