[195132] in North American Network Operators' Group
Re: Long AS Path
daemon@ATHENA.MIT.EDU (Mel Beckman)
Sat Jun 24 08:11:04 2017
X-Original-To: nanog@nanog.org
From: Mel Beckman <mel@beckman.org>
To: James Bensley <jwbensley@gmail.com>
Date: Sat, 24 Jun 2017 12:10:54 +0000
In-Reply-To: <CAAWx_pXqQumg_g0EXUeehdcJY-bz=2MaYq7fzw1w2j8z_ycixg@mail.gmail.com>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
James,
By "experienced by someone else" I mean someone who is not one of your cust=
omers.
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 <jwbensley@gmail.com> wrote:
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> On 23 Jun 2017 17:03, "Mel Beckman" <mel@beckman.org> wrote:
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> James,
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> 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 id=
ea
> that your filtering was causing it.
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> -mel beckman
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> Hi Mel,
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> 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 tr=
y
> and look into it.
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> 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.
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> 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.
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> In relation to the OPs question, long AS_PATH routes can be filtered I ju=
st
> wouldn't bother except for very long paths to drop as little as possible
> and be sure of whY you drop/filter.
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> Cheers,
> James.
