SSH on Nerdsid.com

11 Essential OpenSSH Components

Sat, 29 Nov 2025 20:05:20 +0530

You might have SSHed into servers hundreds of times.

You might have used ssh-add to load keys into your agent.

You might have used scp to copy files back and forth between your machine and server.

But have you ever paused and looked at the bigger picture?

All these commands come from one place — the OpenSSH suite. It’s much more than just ssh and scp.

OpenSSH components

OpenSSH has 11 major components.

10 Steps to Secure a New Linux VM

Wed, 22 Oct 2025 07:09:42 +0000

When you launch a new Linux VM, the level of security you really need depends on your use case. That said, there are some basic steps you can take right after provisioning a new VM, to improve it’s baseline security. Following these steps won’t make your server invincible, but it will make it safe and reduce exposure to common attacks.

1. Update your system

Newly deployed images can contain outdated packages with known vulnerabilities. Start by updating everything:

One Line Command to Create an SSH Key

Thu, 30 Mar 2023 00:00:00 -0800

Of late, I have been creating a lot of SSH keys. I am tired of answering each question that one gets asked during such a process. So, I thought of looking up all the switches (options) for the ssh-keygen command so that I can specify everything at once.

Here is the command:

For bash:

 
 POWERSHELL
 
ssh-keygen -t ed25519 -b 4096 -C "you@mail.com for Gitlab" -N "" -f "/home/usr/.ssh/key"

For powershell:

 
 POWERSHELL
 
ssh-keygen -t ed25519 -b 4096 -C "you@mail.com for Gitlab" -N '""' -f "C:\Users\uname\.ssh\keyname"

Description

The above command generates an SSH key pair using the ed25519 algorithm with a 4096-bit key length, and saves the private and public keys with the specified name (and location).

Setup SSH Authentication for Git on Windows

Mon, 13 Mar 2023 00:00:00 -0800

SSH auth vs password based auth

SSH authentication is generally preferred over password-based authentication for several reasons:

Security: Passwords are easily guessed or hacked, whereas SSH authentication relies on cryptographic keys, which are much more difficult to crack.
Convenience: Once you’ve configured SSH authentication, logging in to a remote system becomes much easier. You don’t need to remember or type in a password every time you log in; instead, you just need to have your SSH key handy.

How to Fix SSH Error: Could not open a connection to your authentication agent

Sat, 07 Jan 2023 07:32:28 +0530

The problem

Recently, I was trying to add a SSH key to the ssh-agent. So, I ran the following command:

 
 BASH
 
ssh-add ~/.ssh/<key_name>

This resulted in the following error:

 
 BASH
 
Could not open a connection to your authentication agent.

The solution

The error message is pretty clear. Since a connection to the ssh-agent could not be opened, first let’s check if the ssh-agent is running or not.

 
 BASH
 
ps -e | grep [s]sh-agent

If the ssh-agent is not running, you will not see any output. This is exactly what happened in my case. So, the solution is simple: you need to start the ssh-agent.