Re: RU evidently hijacked UA netblock

[Erik Sundberg <ESundberg () nitelusa com>]

Here is a doc for each hardware vendor for filtering long as paths. Not sure if this will help you or if the issue is 
before filtering takes place.

We have ours max length set to 75.

https://bgpfilterguide.nlnog.net/guides/long_paths/

Erik

Erik Sundberg
Sr. Network Engineer
Nitel
350 N Orleans Street
Suite 1300N
Chicago, Il 60654
Desk: 773-661-5532
Cell: 708-710-7419
NOC: 866-892-0915
Email: esundberg () nitelusa com
web: www.nitelusa.com
________________________________
From: NANOG <nanog-bounces+esundberg=nitelusa.com () nanog org> on behalf of Scott Weeks <surfer () mauigateway com>
Sent: Friday, March 4, 2022 8:46:47 PM
To: nanog () nanog org <nanog () nanog org>
Subject: Re: RU evidently hijacked UA netblock



--- jay () west net wrote:
On 3/4/22 18:03, Scott Weeks wrote:

> It looks like a 'too many' AS prepends, but it is only 250 prepends.

In most reasonable scenarios I'd say that this qualifies as too many.
---------------------------------------------


Yeah, technically, but it was not 256 or something where I'd expect an issue to happen.  Just curious as to why only 
that ASN caused the buffer overflow messages as I got them from no other AS ever and wondered if anyone else has seen 
them.  Other ASNs almost certainly have sent 250+ prepends to me before, but they did not cause the overflow.  Like I 
said, I have a ticket open because I am curious:

BGP-WARNING-tBgp4RouteInvalid-2007 <stuff> Route invalid reason - Cannot add/prepend AS-path.  Buffer overflow\nNRLI - 
<prefix>  where prefixes are several and different lengths.

Probably nothing, but I always look into stuff I see in the syslog server's router.log.

scott

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