Changing IP addresses in BIND DNS - Hosted Websites affected

[wilsonsr]

We are changing ISPs and are getting a new range of IP addresses. We host our own external DNS (BIND) and also host several websites. The IP addresses of all these websites are going to change. During the transition period both T1 s will be active. I will change the IP addresses for the websites when I change the addresses in DNS.

I want to be able to change an IP address in DNS and ensure that any requests for a website be resolved either to the old or new ip address (due to DNS latency).

Example:

I have

http://www.website.com

that resolves to 66.67.68.69

I change DNS records for

http://www.website.com

to 33.34.35.36

one hour later: request comes to a DNS server somewhere for

http://www.website.com

and that DNS server (not updated yet) sends request to 66.67.68.69

I receive that request for 66.67.68.69 and forward it to the new address 33.34.35.36

Is this possible?

Thanks

 

[spydyr]

You could setup a temporary web server at the old address that would do an html redirect to your new servers.

 

[ChrisAC]

If you lower the TTL's on all the domains to say 600 (10 minutes) then full DNS propagation will take only that long!

Chris.


**********************
Chris Andrew, CCNA, CCSA
chris@iproute.co.uk
**********************

 

[spydyr]

I'm not sure how TTL applies to the root domain servers. I'm thinking it probably won't help. You're best bet is to force a redirect either with a firewall or http. That way no traffic has a potential of being lost.

 

[jsauce]

The theory is that the root servers are suppose to point the request to the dns server that actually has the correct DNS entry. So if at least one server has the correct entry it should then point someone in the right direction, doesn't always work but updating the TTL should help just as long as the serial has been changed to let them know there was a change made.

John D. Saucier
jsauce@magicguild.com
Certified Technician
Network Administrator