How to set ssh timeout?

ssh -o ConnectTimeout=10  <hostName>

Where 10 is time in seconds. This Timeout applies only to the creation of the connection.

try this:

timeout 5 ssh user@ip

timeout executes the ssh command (with args) and sends a SIGTERM if ssh doesn't return after 5 second. for more details about timeout, read this document： http://man7.org/linux/man-pages/man1/timeout.1.html

or you can use the param of ssh:

ssh -o ConnectTimeout=3 user@ip

You could also connect with flag

-o ServerAliveInterval=<secs>

so the SSH client will send a null packet to the server each <secs> seconds, just to keep the connection alive. In Linux this could be also set globally in /etc/ssh/ssh_config or per-user in ~/.ssh/config.

Use the -o ConnectTimeout and -o BatchMode=yes -o StrictHostKeyChecking=no .

ConnectTimeout keeps the script from hanging, BatchMode keeps it from hanging with Host unknown, YES to add to known_hosts, and StrictHostKeyChecking adds the fingerprint automatically.

**** NOTE **** The "StrictHostKeyChecking" was only intended for internal networks where you trust you hosts. Depending on the version of the SSH client, the "Are you sure you want to add your fingerprint" can cause the client to hang indefinitely (mainly old versions running on AIX). Most modern versions do not suffer from this issue. If you have to deal with fingerprints with multiple hosts, I recommend maintaining the known_hosts file with some sort of configuration management tool like puppet/ansible/chef/salt/etc.