On 5 May 2008, at 21:49, Nathan Ward wrote:
On 6/05/2008, at 1:21 PM, Joe Abley wrote:
On 5 May 2008, at 20:50, Nathan Ward wrote:
Perhaps what would make more sense here is Foundry (F5, etc.) building an anycast feature - anycast prefixes are withdrawn when a cluster relying on that anycast prefix goes below a threshold.
I'm not sure exactly what feature is required, here. f5s of my acquaintance are already very capable of making OSPF LSAs based on virtual servers' pools being non-empty. Do it on more than one f5 in the same area, and you're anycasting service availability with the current feature set.
Can they do it with BGP for Internet anycast?
They run ZebOS for routing stuff, so I would say so, although I haven't tried. In our application the covering supernets are synthesised as aggregates based on the presence of the OSPF /32.
The general reason why people prefer to find alternative solutions rather than use dedicated load-balancers are that the dedicated load- balancers are hellishly more expensive than the $5 gigabit switch you probably already have in your garage.
The dedicated load balancers also talk BGP (well, ones I've played with), so that does away with the need for a BGP speaking router.
There is a certain keenness to keep the peering edge free of multi- function boxes in some sandboxes I have played in. I can't say I would be tremendously enthusiastic about the idea of using an (say) f5 BigIP 6800 as a peering router (not that I've tried and failed, or anything; for all I know it would work just fine). But perhaps some of that religion has just rubbed off on me. Joe