Changing static IP

[garydlb]

Hi All,
need some advice.
Currently have static Ip with exchange server 5.5 on a dial up ISDN.
Have just had Adsl installed and have a static IP with this.
Which to cancel the ISDN and just use adsl.
But mx records (for 3 domin names) point to isdn ip.
I could get the mx records changed to point to the new ip etc but from past experience takes a couple of days for everthing to filter through dns servers. Cant really have email not coming through.
So my question is:-
Can I add another network card (currently have 2, 1 for internal network other to ISDN router) and accept mail from the ISDN router and the ADSl router. in other words have 2 external IP addresses for the exchange server, would this work?
thanks for any help

 

[ssay]

what is the TTL on your DNS servers. You could try to reduce the TTL before the change, waite to replicate to other DNS servers, chnage the IP address and then once all is working, then increase the TTL.

 

[brontosaurus]

You can add a second MX record for your mailserver with a "heavier weight" that points to the new IP address. Most DNS servers will "round-robin" the lookups as they are requested. Keep this config for a few days until you're sure that all the info has replicated, then remove the old entry. If that's a bit vague , let me know.