sub cisco_ssh_login {
   my $login_output = "";
   my $enable       = "";
   eval {
      $login_output = $ssh->login();
      if ($login_output !~ /username|password|passcode|#|>/) {
         die "Login has failed.
         Login output was $login_output";
      }
   };
      if( $@ =~ m/SSHProcessError The ssh process was terminated/ ) {
         # Login Failed Leave Sub Routine with value  "ssh_failed"
         return "ssh_failed";
      }
....
}
....
 $login_result = &cisco_ssh_login();
 if ( $login_result eq "ssh_failed") { $login_result = &cisco_telnet_login(); };