Este / etc / network / interfaces funciona para mim em 2.6.32-40 Ubuntu 10.04 LTS:
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 192.168.1.10
netmask 255.255.255.0
network 192.168.1.0
broadcast 192.168.1.254
post-up route add default gw 192.168.1.1 metric 1
pre-down route del default gw 192.168.1.1
auto eth1
iface eth1 inet static
address 192.168.2.10
netmask 255.255.255.0
network 192.168.2.0
broadcast 192.168.2.254
post-up route add default gw 192.168.2.1 metric 2
pre-down route del default gw 192.168.2.1
Eu recebo duas rotas padrão:
root@gamla:/etc/network# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 eth0
0.0.0.0 192.168.1.1 0.0.0.0 UG 1 0 0 eth0
0.0.0.0 192.168.2.1 0.0.0.0 UG 2 0 0 eth1
Observe a métrica. Eu entendi sua pergunta?