Managing an Internet outage
szarka at downcity.net
Mon May 12 13:59:02 UTC 2008
At 03:31 PM 5/11/2008, you wrote:
>We occasionally have a situation where our Internet access is completely
>down. My Manager has asked about the viability of locating a DNS server
>off site, and during a situation when we're down, modifying it so that it
>resolves my entire domain to a single IP address. Web users would be
>redirected to that address, and a web page would explain we're off line.
Here's an alternate solution that might work for you: set up a proxy
server located off-site at the same place (could be on the same host)
as your new off-site DNS server. Configure the new DNS server to hand
out the proxy's IP address as the A record for your web sites. Keep
the TTL for the A records low.
During normal operation, some percentage of requests to your site
would be served from the proxy, and they would be (roughly speaking)
served to the visitors most likely to see a performance benefit. (Of
course, if a large percentage of your traffic involves complex
dynamic pages rather than static pages, graphics, etc., the gain
might not be as large and/or more tuning might be required.) OTOH,
when your connection goes down (ah, Cogent, gotta love 'em), everyone
outside would wind up hitting the outside proxy, which could be
configured to reply with a suitable message in this situation.
More information about the bind-users