Hi,
Agreed, but when you have >100 peers that is still a
fair bit of work. I know technically how to do it and am doing
this with transits but then there are only seven of those. It is not a
question of how or can, but should / is it valuable /
constructive?
The
starting point in the thought process having just done it for transits was right
ok, now how do we sensibly scale this to apply it at IXes without everyone
having to run round contacting everyone else and to see if there was an easier
way of doing things, hence the suggestion. Plus it keeps things nice a
separated, your IX peering sessions announce just the main prefixes, the session
to the "blackhole reflector" can be in a separate peer-group and you only send
the /32s to the reflector. You don't have to worry about who uses which
communities as each member that chooses to peer with the reflector is able to
apply an inbound routemaps of their own choosing to any prefixes they receive
from this reflector at each individual IX.
Given
that an ISP has elected to Complete the attack on a host that is being DoSed,
for whatever reason, and they have chosen to send blackhole announcements to
transit the logical extension seems to be to automate the sending of them to IXs
to try to further cut down on traffic. This seems like a easy way,
internally you just community tag on the trigger box for where you want the
announcement to go, transit, internal, customers, IX all,1 2 not 3 - whatever -
and BGP sends it out. Easy, and a single system to send out all updates when you
choose to and easy to remove when you want to take it out
again.
If you
subscribe to completing the attack as a strategy, then the suggestion seemed
like an easy way of rolling it out to the next logical point after
transit.
Kind
Regards
Ben