Anycast 101

Fri Dec 17 22:53:46 UTC 2004

Paul Vixie wrote:

>since i already know that Iljitsch isn't listening, i'm not interested in
>debating him further.  i would be interested in hearing from anybody else
>who thinks that turning on pplb in a eyeball-centric isp that has multiple
>upstream paths is a reasonable thing to do, even if there were no anycast
>services deployed anywhere in the world.  at the moment i am completely
>certain that turning on pplb would be an irrational act, and would have a
>significant performance-dooming effect on a client population behind it,
>and that the times when pplb would actually be useful and helpful are very
>limited, and that anycast doesn't even enter into the reasons why doing as
>Iljitsch paints would be a bad idea.
>
>but my mind is open, if anyone can speak from experience on the matter.
>  
>
I concur -- it's not reasonable.

We debated these issues to death about PPP multi-link, which could be 
thought of as some variant of a single node talking to 2 (or more)
disparate routers (NAS's are routers, after all).  Can't depend on all
the links attaching to the same dial-in NAS.

Various companies developed protocols to make the NAS's look like a
single router -- otherwise, it wouldn't work.

Plenty of experience.  Has nothing to do with anycast. 

-- 
William Allen Simpson
    Key fingerprint =  17 40 5E 67 15 6F 31 26  DD 0D B9 9B 6A 15 2C 32