[address-policy-wg] Re: Assignments for Critical Infrastruction

On Wed, Oct 29, 2008 at 10:40:37AM +0400,
 Marco Hogewoning <marcoh at marcoh.net> wrote 
 a message of 23 lines which said:

> isn't the whole idea of anycast that you create redundancy by adding
> more machines/locations in the same address space ?

Having one anycast cloud does provide redundancy and then protection
against *some* problems, typically physical problems (power failures,
fire) or dDOS.

> So what exactly are you trying to gain by adding multiple anycast
> blocks, that's not exactly clear with me.

But anycast by itself does not protect you against problems with
BGP/routing. If Pakistan Telecom announces one of your prefixes, or if
a wrong/outdated bogon filter blocks it, anycast by itself won't
help. Here, a second anycast cloud with a second prefix may help.