I'm currently running a LAMP server with 2 IPs provided by 2 different ISPs. I use GoDaddy as my DNS manager but now that I have 2 IP addresses, I need the domain name to resolve the user to the fastest IP address for that specific user.
How do I go about doing this? I think I need an intelligent DNS that can figure out if the user is on the same ISP as the IP addresses.
I started using this service called dnspod.cn. They provide intelligent routing for the different ISP IPs in China via their DNS manager.
If you want, try Ultradns.
Else personally, dont bother. Just create two A records to both IPS and then if you can, set a decent TTL for for the zone.
HTH
Ideally you return both IPs and your user's system would use destination address selection to pick the right one. However, I believe that for IPv4 only some Windows versions do this.
When running your own name server is an option you can use bind with views to provide a different zone for different net ranges.