How to tell if something is anycasted?

Wed May 17 21:21:20 UTC 2006

At 02:11 PM 5/17/2006, Steve Gibbard wrote:

>On Wed, 17 May 2006, Martin Hannigan wrote:
>
>>And there are many, with many TLD's.
>>(rough counts)
>>
>>provider/tld's
>>
>>UDNS 48
>>ISC 19
>>PCH 8
>>PSG 23
>>ICANN 4
>>UUNET 61
>>RIPE 87
>>DEC 10
>>NIC.FR 71
>>
>>Note: There is cross servicing of TLDs counted above.
>>
>>Some numbers may seem low since there seems to be some bit of
>>obfuscation. Or perhaps not and I just haven't confirmed.
>>
>>Some are anycasted, some appear to be physical separations, and some
>>appear to be nested and anycasted i.e. multiple names for the same domain
>>anycasted.
>>
>>I think naming is a bad choice because it's costly to the users and opens
>>the root up to custom configuration by customers which I think is bad.
>>
>>Tagging the route with a community containing the ISO corresponding country
>>could be interesting for location purposes, but of course, that's already
>>been thought of. :)
>
>Of Marty's list above, only UltraDNS and PCH are anycast (there are 
>several other anycast networks hosting TLDs that aren't on Marty's list).

Right. They start to get smaller in numbers and less interesting.

>The numbers there look odd to me.  My data is a six months old (I 
>really need to rerun my script and regenerate it), but my list of 
>/24s and the TLDs they host is at:

>http://www.gibbard.org/~scg/infrastructure-distribution/ranked-dns-subnets-051110
>
>I assume that in most cases a /24 with multiple DNS server IP 
>addresses being authoritative for TLDs is all run by one entity in a 
>common location or set of locations.  UUNet is an exception to the 
>location assumption.

The difference is that you are following the network and I'm following the
operator.

Thanks for sharing your data.

-M<

--
Martin Hannigan                                (c) 617-388-2663
Renesys Corporation                            (w) 617-395-8574
Member of Technical Staff                      Network Operations
                                                hannigan at renesys.com  