Handling telnet timeout/connection refused in pexpect python router - python-2.7

Question

I am trying to write a script where I need to ssh multiple jump server to access a router.
e.g LocalMachine----ssh---server1---ssh---server2---telnet/ssh---router
Not sure what is the best way of doing it, i tried achieving it through pexpect.
My requirement is when i telnet from server server2 to router and it timeout/connection refused i want try ssh
any suggestions please?
import time, pexpect
child = pexpect.spawn('ssh username#server-1') ##########ssh to 1st Jump server
child.expect('password: ')
child.sendline('abc')
child.expect('$')
child.sendline('ssh username#server-2') ##########ssh to 2nd Jump server
print child.before
child.expect('password:')
child.sendline('xyz')
child.expect('$')
print child.before
host=raw_input("Enter Router name: ")
try:
print "Trying Telnet ", host
child.sendline(' telnet ' + host) ### router telnet at this point i want if telnet is timeout/connection refused try ssh
print child.before
except pexpect.TIMEOUT:
print child.before
else:
child.expect(':')
child.sendline("User")
child.expect(":")
child.sendline('passwprd')
child.expect('#')
child.sendline("\n")
child.expect("#")
finally:
print "Trying SSH ", host
child.sendline(' ssh -l User ' + host)
print child.before
child.expect(":")
child.sendline('password')
child.expect('#')
child.sendline("\n")
print child.before
child.interact()

Answer 1

The pexpect.TIMEOUT exception would be raised by the program instance running on your machine. It does not know if there is a timeout for the telnet instance running on the remote machine that you have ssh'ed to. The only way you can see if the telnet connection has a timeout or similar error, ie. connection refused, is to look at the output from the the process through pexpect. If you look at the documentation for expect it says that you can give a list of conditions - this could be one way to go.
For example:
index = p.expect (['timeout', 'connection refused]) # Fill in correct words :)