How to Change the SSH Port on VPS, Common Ports and How to Choose the Right One

Secure Shell (SSH) is a network protocol that allows users to access the server remotely. It also encrypts the communication between a client and private server, making it more secure.

However, using the standard Transmission Control Protocol (TCP) port 22 for SSH might be risky since it is vulnerable to many cyber threats, especially brute-force attacks – a hacking method used to gain access to encrypted sensitive data.

Therefore, changing your default port is one of the best ways to protect your SSH server. In this article, we will explain how to choose a new SSH port and walk you through changing it on your virtual private server (VPS).

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How to Choose a New SSH Port

When choosing a new SSH port, note that port numbers 0-1023 are reserved for various services and can only be bound by root access.

Here is a list of the most common privileged services and their associated ports and functions:

Port	Protocol	Service
20	TCP	File Transfer Protocol (FTP) data
21	TCP	FTP server
22	TCP	SSH
23	TCP	Telnet server
25	TCP	Simple Mail Transfer Protocol (SMTP)
53	TCP/UDP	Domain Name System (DNS)
67/68	UDP	Dynamic Host Configuration Protocol (DHCP)
69	UDP	Trivial FTP (TFTP)
80	TCP	Hypertext Transfer Protocol (HTTP)
110	TCP	Post Office Protocol 3 (POP3)
123	UDP	Network Time Protocol (NTP)
137/138/139	TCP/UDP	NetBIOS
143	TCP	Internet Message Access Protocol (IMAP)
161/162	TCP/UDP	Simple Network Management Protocol (SNMP)
179	TCP	Border Gateway Protocol (BGP)
389	TCP/UDP	Lightweight Directory Access Protocol (LDAP)
443	TCP	HTTP over SSL/TLS (HTTPS)
636	TCP/UDP	LDAP over SSL/TLS (LDAPS)
989/990	TCP	FTP over SSL/TLS (FTPS)

Although you can still use them, doing so will put your SSH connection at risk of network conflict.

Therefore, we recommend choosing from different ports ranging from 1024 to 65535 as they are non-privileged.

How to Change the Default SSH Port

In this section, we will explain how to change your default SSH port in four simple and easy steps.

1. Connect to Your Server via SSH

To do so, run the following command line on Terminal or PuTTy:

ssh username@0.0.0.0

For example:

ssh root@187.234.56.1

Next, you will be prompted to type the password or SSH keys. Once you’ve done so, the connection will be established.

2. Change SSH Configurations

Start by executing the following command to access the SSH daemon (sshd):

sudo nano /etc/ssh/sshd_config

The SSH configuration file will open. Find the line that reads #Port 22. Next, delete the number and # and replace it with the new SSH port number you want to use.

For example:

Change the SSH port number to 1026:

Then save the changes.

3. Configure Your Firewall

Start by making sure the newly selected port is not blocked. If this is a new VPS setup, all ports should be open by default.

Update your firewall settings to allow incoming connections to the new port. For this example, we will be using the UFW firewall. Run the following command:

sudo ufw allow 1026/tcp

Next, restart the SSH service using the following command:

Debian and Ubuntu:

sudo service ssh restart

Debian and Ubuntu with systemd:

sudo systemctl restart ssh

CentOS and Fedora

sudo service sshd restart

CentOS and Fedora with systemd:

sudo systemctl restart sshd

4. Test the New Default Port

To verify that the new SSH port is open, run either the ss or netstat command:

ss -tulpn | grep 1026

netstat -tulpn | grep 1026 

Now you can try to log in to SSH using the following command:

ssh -p [port] user@server

For example:

ssh -p 1026 root@0.0.0.0

Conclusion

Using the default SSH port 22 can make you an easy target for hackers – they often look for open ports through which to intercept and extract sensitive data. Therefore, we recommend changing the SSH port to avoid potential cyber attacks and add extra protection to your Linux server.

Before choosing a new port for your SSH access, note that the ports numbered 0-1023 are reserved for privileged services. Hence, it is best to use a port ranging from 1024 to 65535.

Configuring a new specified port is relatively easy – you only need to update the number in the SSH daemon configuration file and firewall settings. Then, restart the SSH service and test the new port’s connection again.

We hope this article has helped you change your SSH port on VPS. If you have any questions or ideas, please leave them in the comments section below.