Do you know WHY you main link is off?
Perhaps ask the network admins to take a look at it also.
I am just trying to learn too, so take everything I say with a pinch of salt.
From what i can see your main link out is theKiller ->BigBang ->IO2 ->others
If I ping/trace from my side I can see up to IO2 and Redeamer, but i cannot ping Big_Bang
So the problem (im guessing) could be the IO2 -> Bigbang link?
What I find weird is the trace to Big_Bang gets all the way to Puck, then backtracks to Fubar and Fuzzy , and dies.
Hopefully someone who knows whats going on can tell me if my methodology is correct so far?