i am still trying to understand why this is causing so much of a problem,
possibly masking a second bug. but i would appreciate knowing how
widespread the leakage is.
Yep, that one looks familar. I reported it to trouble@mci.net last
October when I was setting up a MBONE tunnel with MCI. In the end
it was easier to just filter those MCI internal networks on my side.
My guess is it leaks across anyone talking to MCI with as-in: ANY, who
doesn't agressively filter. I think this one falls into the catagory,
trust, but verify.