nanog mailing list archives
Re: DMARC ViolationAS21299 - 46.42.196.0/24 ASN prepending 255 times
From: Joe Provo <nanog-post () rsuc gweep net>
Date: Fri, 25 Mar 2022 12:31:34 -0400
On Fri, Mar 25, 2022 at 11:08:01AM +0300, Paschal Masha wrote:
:) probably the longest prepend in the world. A thought though, is it breaking any standard or best practice procedures?
Many popular BGP implementations have historically had weaknesses with excessively long AS-paths. Best practice is to protect ones' infrastructure so many networks drop paths over certain lengths (at various times, 50 or 100 were common due to specific issues). It is highly common for any filtering mechanism, once established, to stay in place, so I fully expect this path to be invible to many and fragile for the rest [see https://blog.apnic.net/2019/07/15/excessive-bgp-as-path-prepending-is-a-self-inflicted-vulnerability/]. That said, prepending pretty much anything more than your current view of the Internet's diameter in ASNs is useless in practice. Cascading effects are considered in https://datatracker.ietf.org/doc/draft-ietf-grow-as-path-prepending/ where a decent low number (5) is propsed. Chers, Joe -- Posted from my personal account - see X-Disclaimer header. Joe Provo / Gweep / Earthling
Current thread:
- AS21299 - 46.42.196.0/24 ASN prepending 255 times Erik Sundberg (Mar 24)
- Re: AS21299 - 46.42.196.0/24 ASN prepending 255 times surfer (Mar 24)
- Re: AS21299 - 46.42.196.0/24 ASN prepending 255 times Erik Sundberg (Mar 24)
- Re: DMARC ViolationAS21299 - 46.42.196.0/24 ASN prepending 255 times Paschal Masha (Mar 25)
- Re: DMARC ViolationAS21299 - 46.42.196.0/24 ASN prepending 255 times Bjørn Mork (Mar 25)
- Re: DMARC ViolationAS21299 - 46.42.196.0/24 ASN prepending 255 times Joe Provo (Mar 25)
- Re: DMARC ViolationAS21299 - 46.42.196.0/24 ASN prepending 255 times Baldur Norddahl (Mar 25)
- Re: DMARC ViolationAS21299 - 46.42.196.0/24 ASN prepending 255 times Jon Lewis (Mar 27)
- Re: DMARC ViolationAS21299 - 46.42.196.0/24 ASN prepending 255 times Baldur Norddahl (Mar 27)
- Re: DMARC ViolationAS21299 - 46.42.196.0/24 ASN prepending 255 times Joe Maimon (Mar 31)
- Re: DMARC ViolationAS21299 - 46.42.196.0/24 ASN prepending 255 times Matthew Petach (Mar 31)
- Re: DMARC ViolationAS21299 - 46.42.196.0/24 ASN prepending 255 times Joe Maimon (Mar 31)
- Re: AS21299 - 46.42.196.0/24 ASN prepending 255 times surfer (Mar 24)
- RE: DMARC ViolationAS21299 - 46.42.196.0/24 ASN prepending 255 times Adam Thompson (Mar 25)
- Re: DMARC ViolationAS21299 - 46.42.196.0/24 ASN prepending 255 times Brian Knight via NANOG (Mar 25)
- Re: DMARC ViolationAS21299 - 46.42.196.0/24 ASN prepending 255 times Matthew Petach (Mar 25)