On Mon, Nov 07, 2022 at 02:47:57PM -0500, Tom Beecher wrote:
Are you taking the stance of "if you don't send us the prefix, then we don't accept the traffic"?
If you were one of my upstreams, and you implemented that, you would very quickly no longer be one of my upstreams.
Yes, I suffer from having two upstreams that each have a shared transit supplier. They are most likely to only have a single best path on their network and i can observe in the flow data it's not the one I expect it to be. I'm not sure how that provider (3356) would make it happen. I can tell you that the uRPF that 7018 does made me not able to utilize one of the providers for outbound traffic because they never opened the proper ticket for routing that IP space until I had side-escalated to some people that could help me after several months. Thankfully it's not a lot of bits but was still annoying to diagnose and triage. - Jared
On Mon, Nov 7, 2022 at 2:22 PM Charles Rumford via NANOG <nanog@nanog.org> wrote:
Hello -
I'm are currently working on getting BCP38 filtering in place for our BGP customers. My current plan is to use the Juniper uRPF feature to filter out spoofed traffic based on the routing table. The mentality would be: "If you don't send us the prefix, then we don't accept the traffic". This has raised some issues amongst our network engineers regarding multi-homed customers.
One of the issues raised was if a multi-homed BGP customer revoked a prefix from one of their peerings, but continued sending us traffic on the link then we would drop the traffic.
I would like to hear what others are doing for BCP38 deployments for BGP customers. Are you taking the stance of "if you don't send us the prefix, then we don't accept the traffic"? Are you putting in some kind of fall back filter in based on something like IRR data?
Thanks!
-- Charles Rumford (he/his/him) Network Engineer | Deft 1-312-268-9342 | charlesr@deft.com deft.com
-- Jared Mauch | pgp key available via finger from jared@puck.nether.net clue++; | http://puck.nether.net/~jared/ My statements are only mine.