Let us assume you are managing a Linux server supporting an
Ecommerce website. Let us also assume that you have secured the server.
You removed telnet from all servers and installed the more secure ssh.
Let us say that the firewall configuration is as follows

conduit permit tcp host 192.168.5.10 eq 80 any
conduit permit tcp host 192.168.5.10 eq 443 any
conduit permit tcp host 192.168.5.10 eq 22 any

Suppose if a lower level tech calls you up at the middle of the night at
your home and says that he cannot ssh into one of the servers. Now you
try to log into the server from home using ssh, the first time you type
the passwd, it asks passwd again. You think you mistyped it and type
again. Now you are allowed into the server. What are the steps you will
take to make sure that the server is fine.

"Fine" isn't exactly descriptive.

Let us assume that you can rephrase this post into a question that you actually want to know the answer to, instead of misposting in the Security forum with open-ended vague questions.

Please, no homework and no cross-posting..