≡ Menu

ssh

How To Fix Offending key in ~/.ssh/known_hosts file

As we discussed earlier in our basic ssh client commands article, when you do ssh to a machine for the 1st time (or whenever there is a key change in the remote machine), you will be prompted to say ‘yes’ for authenticity of host. This feature is controlled using StrictHostKeyChecking ssh parameter. By default StrictHostKeyChecking [...]

{ 35 comments }

When you have the password-less login enabled, you may be either using SSH to execute command in the batch mode on a remote machine or using SCP to copy files from/to the remote machine. If there are some issues with the password less login, your batch program may end up in a loop or timeout. [...]

{ 2 comments }

You can login to a remote Linux server without entering password in 3 simple steps using ssky-keygen and ssh-copy-id as explained in this article. ssh-keygen creates the public and private keys. ssh-copy-id copies the local-host’s public key to the remote-host’s authorized_keys file. ssh-copy-id also assigns proper permission to the remote-host’s home, ~/.ssh, and ~/.ssh/authorized_keys. This [...]

{ 80 comments }

In our previous articles, we discussed how to setup ssh key based authentication to perform ssh and scp without password under the following three scenarios: OpenSSH to OpenSSH OpenSSH to SSH2 SSH2 to SSH2 In this article, I’ll explain how to perform ssh and scp from SSH2 (local-host) to OpenSSH (remote-host) with no password. 1. [...]

{ 3 comments }

SSH Key based authentication setup from openSSH to SSH2

The previous articles (openSSH to openSSH setup, SSH2 to SSH2 setup) explains about how to setup key based authentication on the same version of ssh to perform ssh and scp without entering password. This article explains how to setup SSH key based authentication between different version of SSH (from openSSH to SSH2) to perform ssh [...]

{ 11 comments }

Howto resolve Algorithm negotiation failed issue on SSH

 While performing ssh from a local-host to a remote-host that are on different versions of ssh, it is possible that you may get “Algorithm negotiation failed” message.  In this post, I’ll explain how to resolve this issue from the ssh client.  1. Unable to ssh to remote-host: In this example, when trying to perform ssh [...]

{ 5 comments }

I explained previously how to Perform SSH and SCP without entering password on openSSH. In this article, I’ll explain how to setup the key based authentication on SSH2 and perform SSH/SCP without entering password using the following 10 steps. 1. Verify that the local-host and remote-host are running SSH2. Please note that ssh and scp [...]

{ 13 comments }

Perform SSH and SCP Without Entering Password on openSSH

In this article, I’ll explain how to perform ssh and scp without entering the password using the SSH Public Key authentication with SSH Agent on openSSH There are two levels of security in the SSH key based authentication. In order for you to login, you need both the private key and the passphrase. Even if [...]

{ 50 comments }