nanog mailing list archives

Re: IPv4 Hijacking For Idiots


From: Christopher Morrow <morrowc.lists () gmail com>
Date: Tue, 6 Jun 2017 12:09:08 -0400

On Tue, Jun 6, 2017 at 2:25 AM, Hank Nussbacher <hank () efes iucc ac il>
wrote:
(I think this is really Ron and Bill chatting, but some of the linkage got
lost on the tubes)



I've read article after article after article bemoanging the fact that
"BGP isn't secure",

They're talking about a different problem: ISPs are supposed to configure
end-user BGP sessions per BCP38 which limits which BGP announcements the
customer can make. Some ISPs are sloppy and incompetent and don't do
this.
Unfortunately, once you're a level or two upstream the backbone ISP
actually can't do much to limit the BGP announcements because it's often
impractical to determine whether a block of IP addresses can legitimately
be announced from a given peer.


just a clarifying note: I don't think bcp38 talks about BGP at all,
actually...
I think bill is actually saying:

 "ISPs are supposed to configure bcp38 to filter TRAFFIC from their
customers/peers and BGP filters to limit the scope of the customer routes
sent/received"

I don't think the filtering of customer prefixes/announcements is actually
covered in a BCP though.


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