TWO NIC, TWO Internet sources.. how share??

[Luis Lopez <expertcr@xxxxxxxxx>]

Hello... I have in the server tow NIC

NIC ONE  192.168.1.1
MASK 255.255.255.0
GATEWAY 192.168.1.254
DNS 192.168.1.1

NIC TWO 192.168.2.200
MASK 255.255.255.0
GATEWAY 192.168.2.254
DNS 192.168.2.254

each NIC VLAN have internet acess:

In the squid config in the DNS line i have 192.168.1.1 192.168.1.254 4.2.2.1

if add the DNS of the other VLAN like this
192.168.1.1 192.168.1.254 4.2.2.1 192.168.2.254

is possible have internet access from NIC TWO if the internet in NIC
one is DOWN?

How is possible do this?

BR

P.S. I know is is possible with router table... i don't how make this.