Hi

I would like to change the DNS instantly on my domain so I have no downtime.

I am right in thinking that if I change the Ip address of the domain in the domains Named file to point to the new server, would this work?

Any suggestions on instant changeover?

many thanks!

Correct, any changes you make to the zones on your dns server take effect as soon as you restart bind.

Unless you set the TTL to 1 second, you're going to have a delay as your changes propagate across the internet.

I advise you update your TTL to 1 second, then wait about however long your old TTL was, then change the zone file and restore the TTL value back to something more reasonable (2 - 4 hours)

It's important to note that while many DNS caches will obey this, many have their own minimum TTL set that will override your TTL if it's too small, so as long as you're relying on DNS, you'll always have to deal with propagation time.

I know most servers will cache for a while, but 1 second TTLs minimize the caching. It would be best to set a low TTL but be willing to wait around for the DNS to propagate.