Ssh Disable Host Key Checking

Internal

• ssh

Overview

The ssh client verifies the identity of the host it connects to, by checking its host key. If the remote host is not known to your system - meaning that its host key is not present in ~/.ssh/known_hosts, the ssh client interactively asks you to accept the host key's to be written into the file:

The authenticity of host '[192.168.1.8]:22 ([192.168.1.8]:22)' can't be established.
ECDSA key fingerprint is 83:59:aa:33:10:98:48:f9:12:96:c4:e3:c2:75:50:b6.
Are you sure you want to continue connecting (yes/no)? yes

When run interactively this is usually not a problem, but the behavior could cause problems when ssh is run from a script, so there are situations when we want to inhibit this behavior, by disabling key checking.

Bypass the Interactive Challenge

You can instruct the ssh client to skip the "Are you sure ..." interactive phase and write the key into ~/.ssh/known_hosts without asking.

This is done as follows:

ssh -o "StrictHostKeyChecking=no" ...