[nsp] designs for site-to-site failover?

From: Steve Francis (steve@expertcity.com)
Date: Wed Oct 10 2001 - 10:52:57 EDT


I don't know if this is an appropriate topic for this list, so if
there's a better place, please let me know...

Basically I want to know what other people are doing for site-to-site
data center failover.

We have an ASP type service, and data centers in New York and San Francisco.

Currently the NYC data center doesn't provide all the services of SF.
All our public IP addresses are within a /24 at SF.

In event of a disaster, what ways could I move service to NYC?
Options I see are:
 - originate the same network into BGP out of NYC. This is my preferred
idea right now, but the concern is how many ISP's implement route
filtering so they'd refuse a /24 that was de-aggregated? The /24 is in
the old class A range...
- DNS type failover, where we keep a short TTL on our A records, and
edit them (manually or via some load balancing Global Director type
thingy) to move where people go. (Little trials I did with this found
that lots of clients seem not to pick up new DNS info very quickly,
despite short TTLs, and need order of days to switch.)

Any other options?
Pro's/Cons of each?

Thanks



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