nanog mailing list archives
Re: DMARC ViolationAS21299 - 46.42.196.0/24 ASN prepending 255 times
From: Baldur Norddahl <baldur.norddahl () gmail com>
Date: Fri, 25 Mar 2022 21:51:21 +0100
On Fri, 25 Mar 2022 at 17:32, Joe Provo <nanog-post () rsuc gweep net> wrote:
That said, prepending pretty much anything more than your current view of the Internet's diameter in ASNs is useless in practice.
That is one way of viewing it. But prepending can also be used for traffic engineering. I could prepend 1 to my free peers, 2 to my paid peers, 3 to cheap ip transit, 4 to expensive ip transit etc. The linked draft RFC does not appear to discuss this at all. The depth of prepending used this way only relates to how many different classes of peers you can imagine in your setup and is not at all related to the "internet's diameter". To someone on the other side of the planet, who are neither peers nor customers of peers, they will just observe that I am prepending 3 or 4 times and wondering why the extra prepends? The answer is that closer to my home there are people who are observing the same routes with 1 or 2 prepends and that it matters. The draft RFC lists some alternatives to prepends of which none can do anything of the sort I just described. Regards, Baldur
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)
- Re: DMARC ViolationAS21299 - 46.42.196.0/24 ASN prepending 255 times Amir Herzberg (Mar 25)