Please see the PNG file I attached. What you see is a redundant connection between the A and the B site. There is no routing protocol running between the A and the B site. The links between the A and B site are running over a set of switches. The problem with this setup is that for example when the link between switch S2 and site B (R4) goes down the link between S2 and site A (R2) will still be up and the link will not be removed from the routing table of R2, the network will not converge.
TCL scripting is not possible on a 3550/3560 switch.
It is not possible to run a routing protocol between the A and B site, static routing is used.
UDLD make no sense in this situation.
Is there a way to solve this problem?