Is there a methodical way to check full reachability?

Guys,
I always have trouble when I get asked to "check reachability in the enterprise network". To me, this implies I have to check every node can reach every over node on the network. Having to note down the contents of the routing table on each device and comparing them all manually to see if anythings missing, let alone ensuring reachability to each node on each network is a mammoth task! Is there some quick methodical process to do this without getting overwhelmed? I'd like to hear how people achieve this very important task.
Thanks in advance!
Joe

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Received on Thu Jan 21 2010 - 06:24:39 ART