North American Network Operators Group

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Re: Alternative to BGP-4 for multihoming?

  • From: Alex Pilosov
  • Date: Wed Mar 01 15:49:43 2000

On Wed, 1 Mar 2000, David Israel wrote:

> The documentation is pretty vague on a few points, but it looks like
> all it does is NAT and (possibly, it's very bague on this point) resolve
> DNS for servers based on what it thinks is the best path to use. There's
> just a static route on your side; the customer gets a network from each
> ISP, and the LinkProof NATs to whichever network it thinks is best.
> Good points: He isn't peering with you. You don't need to do anything
>   to support this. Just statically route him and let him do the rest.
> Bad points: He asked if you support it; ergo, he doesn't know how it
>   works. Prepare your NOC/customer service folks for this guy to call
>   in and bitch if the thing fails. It's also wasteful of IP addresses
>   if the guy's got a big network back there, since he has to number
>   every machine seperately for every connection he's got. Lastly, they're
>   really vague in the online docs on how, exactly, they redirect traffic
>   going to the customer. They just say they redirect it, and later say that 
>   the box will be "taking responsibility for... DNS support for resources
>   that need to be accessed from the Internet." Sounds iffy to me.
> In short, if it were my customer, I'd say something like, "It's your
> funeral. Have a ball." Only I'd say it nicely.

Oy. This stuff seems similar to what I ran on my home network(NAT plus
smart DNS servers that gave out IPs on the links that were up). It worked
semi-decent, only that failover sometimes took ages because of all the DNS
caches in the world which don't care which TTL you set, or have a notion
of 'minimal TTL' below which they won't accept your records, end clients
caching records infinitely (well, until the next reboot/app restart).

All in all, I'd say it works in 95% of cases, and certainly good enough
for home network, but using it in enterprise connectivity is silly.

Alex Pilosov            |
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