I am looking for a tool to compare running configs on cisco routers? I want to do it live for about 35 of our common routers. comparing 2 at a time is fine. Only things I can find in the toolset want to comare startup and running on same unit.

I am wanting to be able to compare running configs across multiple routers concurrently.  The doc I can find says it can do it, but everything I can find compares running to startup.  Any answers to clear up the haze?