[150973] in North American Network Operators' Group
Re: Questions about anycasting setup
daemon@ATHENA.MIT.EDU (Bill Woodcock)
Fri Mar 9 01:55:45 2012
From: Bill Woodcock <woody@pch.net>
In-Reply-To: <CAJ0+aXZqZrGxXw7mzKmopU9PoZ9Gfk00TmZSzH=0SBGBdCuJyg@mail.gmail.com>
Date: Thu, 8 Mar 2012 22:54:32 -0800
To: Anurag Bhatia <me@anuragbhatia.com>
Cc: NANOG Mailing List <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256
Hello, Anurag.
On Mar 8, 2012, at 9:51 PM, Anurag Bhatia wrote:
> 1. For anycasting does announcing a /24 from different ASNs (of
> different datacenters) makes sense or it will be an issue to have a =
block
> being announced from different ASNs?
Keeping a consistent announcing ASN for your prefix is thought to be =
best-practice, and if you don't do so, eventually there will be people =
who will undoubtedly complain, but there is no technical difficulty with =
announcing your same prefix from multiple origin ASNs. Any difficulties =
you encounter will be because of people aggressively filtering what they =
choose to listen to.
> 2. We plan to use this anycasting based setup for DNS during initial =
few
> months. Assuming low traffic for DNS say ~10Mbps on average (on =
100Mbps
> port) and transit from just single network (datacenter itself) - is =
this
> setup OK for simple software based BGP like Quagga or Bird?=20
Yes, and in fact, that's how nearly all large production anycast =
networks are built=E2=80=A6 Each anycast instance contains its own BGP =
speaker, which announces its service prefix to adjacent BGP-speaking =
routers, whether those be your own, or your transit-provider's. Doing =
exactly as you describe is, in fact, best-practice.
> 3. IPv6! - Is /32 is standard? We have only one /32
> allocation from ARIN and thus if using /32 seems like hard deal - we =
have
> to likely get another /32 just for anycasting? or we can use /48 =
without
> issues? Also, is /48 a good number for breaking /32 so that we can =
do /48
> announcements from different datacenters in simple uni casting =
setup?
A /48 is quite reasonable. Announcing a whole /32 just for your anycast =
service would be wasteful.
Good luck!
-Bill
-----BEGIN PGP SIGNATURE-----
Version: GnuPG/MacGPG2 v2.0.17 (Darwin)
Comment: GPGTools - http://gpgtools.org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=3D4Yhn
-----END PGP SIGNATURE-----
