chainssh is a shell script to smplify the ssh login via multiple sshgateways/firewallgateaways.

Operating System: All POSIX (Linux/BSD/UNIX-like OSes), Linux, OpenBSD, AIX, HP-UX, Solaris
License: GNU General Public License (GPL)

e.g. if the connect to a clusternode is done via ssh over a sshgateway 
and a firewall the ssh command is like thes:

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homeuser@homews /home/homeuser > ssh -l fwuser firewallhost
Enter passphrase for key '/home/homeuser/.ssh/id_rsa':
fwuser@firewallhost's password:
Letzte erfolglose Anmeldung: Do 27 Jul 18:32:11 2006 bei ssh von homews
Letzte Anmeldung: Do 27 Jul 18:41:37 2006 bei ssh von homews

*******************************************************************************
* *
* *
* Welcome to AIX Version 5.1! *
* *
* *
* Please see the README file in /usr/lpp/bos for information pertinent to *
* this release of the AIX Operating System. *
* *
* *
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fwuser@firewallhost /home/fwuser > ssh -l sshgwuser sshgateway
Kennwort von sshgwuser@sshgateway:
Letzte erfolglose Anmeldung: Do 27 Jul 18:33:14 2006 bei ssh von firewallhost
Letzte Anmeldung: Do 27 Jul 18:41:41 2006 bei ssh von firewallhost

*******************************************************************************
* *
* *
* Welcome to AIX Version 5.1! *
* *
* *
* Please see the README file in /usr/lpp/bos for information pertinent to *
* this release of the AIX Operating System. *
* *
* *
*******************************************************************************
sshgwuser@sshgateway /home/sshgwuser > ssh -l adminuser clusternode1
Kennwort von adminuser@clusternode1:
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* *
* *
* Welcome to AIX Version 5.3! *
* *
* *
* Please see the README file in /usr/lpp/bos for information pertinent to *
* this release of the AIX Operating System. *
* *
* *
*******************************************************************************
********************************************************************
********************************************************************
** **
** ADMIN User **
** **
********************************************************************
********************************************************************
adminuser@clusternode1 /home/adminuser W_SM_V4.1#exit
logout
Die Verbindung zu clusternode1 wurde geschlossen.
sshgwuser@sshgateway /home/sshgwuser > exit
logout
Die Verbindung zu sshgateway wurde geschlossen.
fwuser@firewallhost /home/fwuser > exit
logout
Connection to firewallhost closed.
homeuser@homews /home/homeuser >

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with sshchain it is just one command:
homeuser@homews /home/homeuser > chainssh -l adminuser clusternode1
*******************************************************************************
* *
* *
* Welcome to AIX Version 5.3! *
* *
* *
* Please see the README file in /usr/lpp/bos for information pertinent to *
* this release of the AIX Operating System. *
* *
* *
*******************************************************************************
********************************************************************
********************************************************************
** **
** ADMIN User **
** **
********************************************************************
********************************************************************
adminuser@clusternode1 /home/adminuser W_SM_V4.1#exit
logout
Die Verbindung zu clusternode1 wurde geschlossen.
Die Verbindung zu sshgateway wurde geschlossen.
Connection to firewallhost closed.
homeuser@homews /home/homeuser >