I think it would have been more helpful to start with multi-hop. Since there are many ways to connect and no guarantee that the same protocol (telnet, ssh, rlogin, etc) will be used between hops, the only technique is to carry the originating IP with each hop. The only way I know how to do this is with telnet. There is a little known (but sometimes frustrating) option in telnet that carries the current value of TERM to the next destination. So you could do something like this:
TERM=10.11.12.13 telnet nexthop
You'll have to capture $TERM at the top of /etc/profile and save it off for the next hop.
Or run multiple single sessions. I can't tell you how many sysadmins accidentally shutdown the wrong server due to server hopping. I routinely have 5 to 10 PuTTY sessions, all with unique colors using either Connection Manager or Session Manager.
Bill Hassell, sysadmin