connecting two routers to use two different ips

[24seven]

i have two router a linksys and a vsp 5002 . i need to connect them so that both can be using two different real ips but the same DNS for internet connection. so that if one ip is down it wont affect other. Nb am using a Vsat Connection. i will be gald if some give a solution to this

[DVNT1]

I would like to help but I do not understand.. . "Nb am using a Vsat Connection"

[24seven]

am using a Shiron gateway but i think you can go ahead an explain the connection is not all that important now

[DVNT1]

Modify the DNS settings to choose one router LAN IP as Primay DNS server and the other as Secondary DNS server. Do this within the DHCP scope options on your DHCP server or else at the individual clients.