How to SSH with a Different Username on Ubuntu

When connecting to an Ubuntu Linux machine via SSH, the client automatically attempts to log in using your current local system’s username. However, if your remote account name differs, you must explicitly specify the correct username to establish a successful connection. This article explains the standard terminal commands, flag options, and configuration file shortcuts to connect to your Ubuntu server using a different username.

Method 1: Specify Username in the SSH Connection Command

The most common and straightforward way to connect with a different username is to define it directly within your SSH command. You can do this using two different syntax options.

Option A: Using the username@ Syntax

This is the standard and most widely used format. You simply prefix the target IP address or domain name with your desired username, separated by an @ symbol.

ssh username@remote_host_or_ip

For example, to connect to an Ubuntu server at 192.168.1.50 as the user ubuntu:

ssh ubuntu@192.168.1.50

Option B: Using the -l (Login Name) Flag

Alternatively, you can use the -l flag followed by the username you wish to log in as. This is useful if you prefer to keep the hostname separate.

ssh -l username remote_host_or_ip

Using the same example as above:

ssh -l ubuntu 192.168.1.50

Method 2: Configure the SSH Config File for Automatic Login

If you frequently connect to a specific Ubuntu machine, typing the username every time can become tedious. You can automate this process by editing your local SSH configuration file.

1. Open (or create) the SSH config file on your local machine using a text editor:

   nano ~/.ssh/config

2. Add the following block of code, replacing the placeholders with your actual server details:

   Host myubuntu
       HostName remote_host_or_ip
       User username

3. Save and close the file (in Nano, press Ctrl+O, Enter, then Ctrl+X).

4. Now, you can connect to your Ubuntu server using the nickname you defined, without needing to specify the IP address or username:

   ssh myubuntu

Method 3: Specifying a Different Username with an SSH Key

If your Ubuntu server requires an SSH key for authentication, you can combine the username specification with the identity file (-i) flag:

ssh -i /path/to/private_key username@remote_host_or_ip

For example:

ssh -i ~/.ssh/id_rsa ubuntu@192.168.1.50