Remember to replace "eth0" with your NIC device although usually it will be eth0.
Replace 192.168.1.1 with your default gateway, remember you can also add multiple gateways by adding a second/different default gateway.
route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 * 255.255.255.0 U 1 0 0 eth0
link-local * 255.255.0.0 U 1000 0 0 eth0
default DD-WRT 0.0.0.0 UG 0 0 0 eth0
route del default gw 192.168.1.1 eth0
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 * 255.255.255.0 U 1 0 0 eth0
link-local * 255.255.0.0 U 1000 0 0 eth0
route add default gw 192.168.1.1 eth0
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 * 255.255.255.0 U 1 0 0 eth0
link-local * 255.255.0.0 U 1000 0 0 eth0
default DD-WRT 0.0.0.0 UG 0 0 0 eth0
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