maybe i'm dense when it comes to things operational, you'd have
to ask our noc as they probably have an opinion :-), but i can't
imagine why our noc would want to troubleshoot someone elses
connectivity problem. i would think that whatever the problem
being diagnosed, the noc involved would be the noc of the network
which is black-holing traffic or being black-holed and would
therefore know about any filtering present.
i think that it's our duty to keep a good list of mac addr's on
our filter if we choose to filter and to inform those networks
with whom we have peering arrangements of the existence of that
filter. that way, if the one of our peers changes hardware and
does not keep the same mac layer address, we can change the filter
to include them.
i haven't heard a case against filtering yet (third party routing,
etc.) that didn't fall into the category of things that filtering
is supposed to prevent. if filtering goes into place and you're
doing something non-standard at one of the interconnects, either
come clean with the parties involved or...
Jeff Young
young@mci.net