Bill, woody@pch.net (Bill Woodcock) wrote:
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?
Yes, and in fact, that's how nearly all large production anycast networks are built??? 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.
Well, let's say, using Quagga/BIRD might not really be best practice for everybody... (e.g., *we* are using Cisco equipment for this) Using anycasting for DNS is, to my knowledge, best practice nowadays.
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.
Why? It's simply another prefix, no matter how big. It might look wasteful, but if *that* is the allocation you *have*, it's the one you ought to use. One should be careful - people do filter on allocation lengths, so breaking out a /48 out of a /32 allocation and advertising it on its own can lead to it being filtered. Elmar.