Simplest explanation is that you can't do a 'show run' from global configuration mode....
try something like #exit global configuration mode tn.write('end\n') print tn.read_until('#') #disable pause after 24 lines tn.write('term len 0\n') tn.read_until('#') #now show the entire running-config tn.write('show run\n') print tn.read_until('#') -- http://mail.python.org/mailman/listinfo/python-list