"Virtual" multi-homing providers

Fri Oct 5 18:26:31 UTC 2001

Your biggest problem will be getting address space, for that few servers,
that is globally routable. Your other issue, is getting transit from
multiple carriers - an Equinix or PAIX is your best bet for this sort of
thing.

What you are describing can be done, BGP-wise in two way. One way is to have
discrete address space for each POP, and run discontiguous eBGP, using the
same AS in each POP. To defeat bgp loop detection, and ensure each POP is
reachable from the others, you need a default route point towards your
transit providers.

The other popular method for doing this, is running Confederation BGP, with
each POP as a sub-AS, and GRE tunnels between POPs.

I personally prefer #1, but it's harder from the IP addressing angle. Both
work, and work well. You will need to announce a larger aggregate out, at
least one POP, of /20 or above, to deal with the few ISPs that filter on
those boundaries. If at least one of your ISPs is the same in each location,
you can limit some of the sub-optimal routing that might result.

- Daniel GOlding

> -----Original Message-----
> From: owner-nanog at merit.edu [mailto:owner-nanog at merit.edu]On Behalf Of
> Ng Pheng Siong
> Sent: Friday, October 05, 2001 1:10 PM
> To: nanog at merit.edu
> Subject: "Virtual" multi-homing providers
>
>
>
> Hello,
>
> I'm looking at deploying "POPs" at several IDCs across the globe.
>
> Each POP will contain several servers. (At most ten.) I would
> like each POP
> to use the same set of IP addresses; connections to these IP
> addresses will
> get to the nearest POP by virtue of routing.
>
> IOW, I think I'm wanting to have all my POPs belong to one AS, as if said
> AS multi-homes to each POP/IDC, except that the multi-homing is virtual,
> because I don't have links from my "enterprise network" to these IDCs.
> (Well, I don't expect to have much of an enterprise network. ;-)
>
> Are there providers of such? Will I be able to get a globally routable IP
> block for my AS? Or is my best bet to pick one provider which has global
> presence? (Which such global providers are there? Do people like Exodus or
> Digital Island count?)
>
> TIA for your input. Cheers.
> --
> Ng Pheng Siong <ngps at post1.com> * http://www.post1.com/home/ngps
>