Peering multi-platforms

Well... Myself...

If I were doing it, I'd take a config from the 1500 and move it to a lab and do a trial restore to the 1600. See what breaks. Fix it up manually... (And if you have a config that changes a lot, write q quick script to do whatever fixups are required. Possibly none, especially if the changes required are only in the shared config).

Then, unless your testing of keeping the 1500 and 1600 in sync are successful, I'd put the 1600's in, but disable the switchports. Then to cutover, simply disable the 1500 switchports and enable the 1600's... You'd lose any active connections, but it's a single loss of service. That;s only if the sync between 1500 and 1600 is unsuccessful mind you... You could be lucky there. But YMMV of course...

The last time I had to do this, it was from 4.5 on 5000's to 9.1 on 6400's... That HAD to be turn off one and turn on the other. But the outage time can be down to seconds (Or as long as it takes to type

int 1
shutdown
int 2 
no shut

(As long as you setup everything else in advance).

H