Wildcard CNAME

[Danny Mayer]

At 04:51 PM 10/30/02, Warrick FitzGerald wrote:
>Hi All,
>
>I currently sit with a rather painful DNS problem that I am hoping some
>someone can help me with.
>
>We provide a solution for our clients to point a domain ... lets say X.com
>to one of our IP Addresses and then based on the prefix of the domain used,
>we generate content on our web pages dynamically.
>
>The problem with this solution is that they currently setup an A Record that
>looks something like this
>
>*.X.com    IN    A    200.200.100.50
>
>This of course works fine and dandy until you need to change the IP Address
>that these users are pointed at :( ... At which time I start phoning
>customers and organizing the largest project management nightmare you have
>ever seen.

Why? You keep the old address and the new address until the addresses
expire out of cache. It takes time and you can reduce the TTL value several
days before in order to speed up the expiry of the old records in other
people nameservers' caches.

>My ideal solution would be of my client to have a wildcard CNAME setup  ...
>something like this :
>
>*.X.com    IN    CNAME    Domain.ThatIControl.com
>
>Then of course I would have an A record on my End that would be
>
>Domain.ThatIControl.com   IN    A    200.200.100.50

There's no point to this. The record still has to expire out of cache and
it will take just as long.


>---------------
>
>I have spoken to our DNS vendor about this .... and the response that I got
>was that RFC 1034 does not support this ... can someone please explain why
>to me ... or even better suggest a better solution.

See above. You shouldn't be changing IP addresses that often anyway.

Danny

>Thanks
>Warrick FitzGerald
>LiveTechnology Holdings Inc.