DNS question - A/CNAME priority

[Hokey]

Tek-Tips does not have a DNS forum ... so I figured that I would ask this question here.

Getting a reliable ISP in my area has been quite a task. I currently have three ISPs that feed different parts of my server farm Internet connection (servers 1-5 go through ISP1, 6-8 ISP2, 9&10 through ISP3). At least once a week, one of the ISPs will go down for several hours (for various reasons). Durring their down-time, I loose all business on the servers effected (not to mention piss off my customers). I have set up my internal routing so I can quickly change the feeds to the servers at the drop of a hat, but my problem is DNS.

My DNS setting are setup so the "A" or "CNAMES" of each server points to the address from the ISP of that servers feed. What I am looking at doing is setting some type of priority (like the MX records have) so if the address from their main ISP is not available, customers will automatically be redirected to a different ISP.

Is this possible?

 

[IPconfig]

Yes this is possible in a way .. well i assume you want to be redundant in a way so that you have like a couple of nameservers going in case one lets you down what you can do is in the main Nameserver you can specify the Name server e.g

;Name server
IN A ISP1
IN A ISP2
IN A ISP3

something like that ..but these records offcourse have to be in the main db of the ISP's Nameserver so when you set up a clients box you put in all the alternative Nameservers so that they dont get any problems.....

i hope this helps