IPv4 Anycast?

Jack Bates jbates at brightok.net
Wed Apr 22 08:01:16 CDT 2009

Zhenkai Zhu wrote:
> Then there is basically no inter-As anycast besides the anycast prefix 
> for DNS root, since I only noticed like 8 prefixes that are announced by 
> more than 3 ASes..

I presume you are using route-views or some such to get a larger picture 
of the BGP geography? I believe that many anycasts utilize the same ASN 
for their anycasted address space. I would expect that a few of them 
have an ASN specifically for their anycasted space.

  Given that the networks are duplicates, there's no requirement that 
one part of the AS needs to receive routes from the other part of the 
AS. For management and such of the devices, I presume there are separate 
netblocks advertised with a different ASN (possibly even statically 
assigned by a hosting network).


More information about the NANOG mailing list