I have this in my interfaces file:auto eth1iface eth1 inet static        address 20.135.251.218        netmask 255.255.255.252        up route add default gw 20.135.251.217 dev eth1 metric 1If I run ifconfig eth1 down, the default gateway is removed from the routing table. But when I do ifconfig eth1 up, the default gateway is not added to the routing table. I have two default gateways with different metric, so only the other gateway appears in the routing table. I have set gc_timeout as 10. I'm trying implemet a solution mentioned in the answer to this question. how can I automatically add the default gateway when I bring up the interface?
Bringing up an interface does not add default gateway to the routing table in Ubuntu
networking;routing