Hi, On Mon, Jan 19, 2004 at 05:45:51PM +0100, Joao Damas wrote:

This goal could very well be achieved by keeping the addresses of the servers you are already using and migrating all other active IP's out of the /24 that contains the address you want to "anycast". After all, none of the root servers that are anycasting today have renumbered (one that is not anycasting today will renumber soon because they can't apply what I just described, which was unfortunate).

For the root servers, this is a viable approach (as you can't easily change their IP address). I'm not sure how useful this approach would be for a typical ccTLD that hosts their existing name servers in the PA address block of some hosting provider.

The problem is then with obtaining a /24 for each anycasted site, not for the service IP but for the "management" IP, something that allows you to uniquely identify the different incarnations of the the same IP, geographically distributed and only accessible through networks other than your own (for the operator of the anycast service, anycast is indeed different from multi-homing). Depending on the requirements for independence (in its various aspects), you may use an IP inside someone else's PA block for that, if you buy hosting from them, for instance, or you may need to ask for a separate /24. It is this last part that may pose a problem within current RIPE policies.

This specific solution (a separate /24 per anycast *instance*) would indeed *also* be a problem under the current policy, but this can be solved - as you suggested - by going for "local" PA addresses. The problem is really the anycast space - you need a routeable /24 (as far as anybody can promise "routeability") for a single host, and the current PI policy won't give you that. Gert Doering -- NetMaster -- Total number of prefixes smaller than registry allocations: 58081 (57882) SpaceNet AG Mail: netmaster@Space.Net Joseph-Dollinger-Bogen 14 Tel : +49-89-32356-0 80807 Muenchen Fax : +49-89-32356-299