James, By "experienced by someone else" I mean someone who is not one of your customers.
The better strategy, I think, is to not filter long paths unless you have a reason to see their creating a problem. Otherwise you're just operating on superstition, no? -mel via cell > On Jun 24, 2017, at 12:42 AM, James Bensley <jwbens...@gmail.com> wrote: > > On 23 Jun 2017 17:03, "Mel Beckman" <m...@beckman.org> wrote: > > James, > > The question is whether you would actually hear of any problems. Chances > are that the problem would be experienced by somebody else, who has no idea > that your filtering was causing it. > > -mel beckman > > > Hi Mel, > > For us this the answer is almost definitely a yes. We are an MSP (managed > service provider) as opportunities to a traditional ISP, so our customers > know they can open a ticket with us for pretty much anything and we'll try > and look into it. > > We have had some weird issues with far away sites, first line can't find > any issue, it works it's way up to somebody who knows how to check if we > would be filtering a route on our transit and peering sessions. > > Earlier when I said that care is required when filtering long AS_PATH > routes or certain AS numbers, we looked at the BGP table to see exactly > which routes we'd drop before hand and communicated out these changes. I > think for an MSP this shouldn't be hard to implement and manage, I can > appreciate for a "flat" ISP ("he's some transit, help yourself") it could > be more challenging. > > In relation to the OPs question, long AS_PATH routes can be filtered I just > wouldn't bother except for very long paths to drop as little as possible > and be sure of whY you drop/filter. > > Cheers, > James.