BGP has no way to know that an internal network problem occurred. If someone mistakenly tripped over a network cable that disconnected DNS clusters from a router, how would the router know to drop anycast advertisements?
(Sure, you could run zebra on the cluster. But what about if the name server SEGVs? There's a lot of possible scenarios....)
ALmost there.. just make sure your zebra IGPs are redistributing to your BGP so that a failure such as that knocks out the bgp too
Steve
Sorry no zebra. Perhaps I should run my TLDs DNS service on my Juniper Routers. some expect/cron work should provide the needed glue... Now if I could just get cisco to add authoritative DNS service to IOS, right up there with the HTTP, firewall, content caching, and load-balancing cruft they have added to their basic routing code... I could use cisco too! (may still need some glue tho) In case it was not clear, I think that multi-tasking hardware might be the wrong choice. I want my routers to route and not do apps work. For apps, I want them to be single-app specific. DNS service on its own hardware, NTP on its platform, HTTP outsourced to (vendor), etc. This has impact on the design of anycast solutions. Ultra has one model, ISC has another, and PCH uses a third. The more generic content crowd has its favorites. Then there are the "load-balancing" vendors who cater to these folks. One size does not fit all. --bill