Hello,
we use BGPMon.net to monitor our BGP announcements. This morning we
received two possible BGP MITM alerts for two of our prefixes detected by a
single BGPMon probe located in China. I've reached out to BGPMon to see
how much credence I should give to an alert from a single probe location,
but I'm interested in community feedback as well.
The alert detailed that one of our /23 prefixes has been broken into /24
specifics and the AS Path shows a peering relationship with us that does
not exist:
131477(Shanghai Huajan) 38478(Sunny Vision LTD) 3491(PCCW Global) 14042 (me)
We do not peer directly with PCCW Global. I'm going to reach out to them
directly to see if they may have done anything by accident, but presuming
they haven't and the path is spoofed, can I prove that? How can I detect
if traffic is indeed swinging through that hijacked path? How worried
should I be and what are my options for resolving the situation?
thanks!
-andy
Hi Andy,
It smells like someone in 38478 or 131477 is using Noction or some other
BGP "optimizer" that injects hijacks for the purpose of traffic
engineering. 
Kind regards,
Job
Interesting. We also got similar BGPMon alerts about disaggregated portions of couple of our prefixes. I didn't see any of the bad prefixes in route-views, though.
The AS paths in the alerts started with "131477 38478 ..." and looked valid after that. Job's suggestion would explain that.
Steve
Interesting. We also got similar BGPMon alerts about disaggregated
portions of couple of our prefixes. I didn't see any of the bad prefixes in
route-views, though.
The AS paths in the alerts started with "131477 38478 ..." and looked
valid after that. Job's suggestion would explain that.
Looking back at a bunch of historical route leak incidents... they often
seem to be this sort of thing I think I normally term them; "internap
box problems"
I think internap doesn't even really sell that product anymore though so
now I'll call them 'noction problems' instead I guess.
lack of outbound route filtering can be painful yo!
Hi Steve and Job,
Same here- I didn't actually see my prefixes leaked anywhere I could
check, but I couldn't check near China where BGPmon's probe was
complaining. So I was glad it didn't seem to be spreading, but still
concerned that there may have been a large area (China) where my traffic
was getting hijacked.
The alert did clear after around 18 minutes.
Presuming it was a route optimizer and the issue was ongoing, what would be
the suggested course of action? reach out to those 2 AS owners and see if
they could stop it? Or is it something I just have to live with as a
traffic engineering solution they are using and mark the alerts as false
positives?
thanks!
-andy
FYI - I did get a response back from BGPMon- they concur with Job:
"Hi Andy,
unfortunately we had a peer sending us a polluted BGP views. Most likely
using a BGP optimizer that is making up new paths.
We've reached out to 131477 and dropped the session with them.
This was most likely 131477 making up the paths. And not seen wider on the
Internet.
We'll work on making sure that cases like this will not cause bgpmon alerts
going forward, by detecting these false alerts better."
-andy