How to fix ssh_dispatch_run_fatal?

On a Linux 8 system with FIPS enabled, connecting to a Linux 6 system fails, ssh -v displays the following message

ssh_dispatch_run_fatal: Connection to XXX port 22: invalid argument

Solution

The simplest solution is to delete file /etc/ssh/moduli on the Linux 6 system serving as sshd backend.

The same workaround is applicable for other Linux 8 FIPS clients connecting to non-FIPS servers using this key exchange method.

Understanding SSH known_hosts File with Examples

4 Steps to login Linux server without password

4 Steps to login Linux server without password