Assume you want to route the traffic for network 192.168.5.0 through interface eth1 serving 192.168.1.0 network Verify current routing info : [root@gract1 Desktop]# ifconfig eth1 eth1 Link encap:Ethernet HWaddr 08:00:27:29:54:EF inet addr:192.168.1.111 Bcast:192.168.1.255 Mask:255.255.255.0 [root@gract1 ~]# netstat -rn Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth1 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth2 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 192.168.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth2 192.168.3.0 0.0.0.0 255.255.255.0 U 0 0 0 eth3 [root@gract1 ~]# ping 192.168.5.50 PING 192.168.5.50 (192.168.5.50) 56(84) bytes of data. From 192.168.1.111 icmp_seq=2 Destination Host Unreachable From 192.168.1.111 icmp_seq=3 Destination Host Unreachable From 192.168.1.111 icmp_seq=4 Destination Host Unreachable Add routing info : [root@gract1 ~]# ip route add 192.168.5.0/24 dev eth1 [root@gract1 ~]# netstat -rn Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth1 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth2 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 192.168.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth2 192.168.3.0 0.0.0.0 255.255.255.0 U 0 0 0 eth3 192.168.5.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 Verify that ping and nslookup are working [root@gract1 ~]# ping 192.168.5.50 PING 192.168.5.50 (192.168.5.50) 56(84) bytes of data. 64 bytes from 192.168.5.50: icmp_seq=1 ttl=64 time=0.929 ms 64 bytes from 192.168.5.50: icmp_seq=2 ttl=64 time=0.264 ms --- 192.168.5.50 ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 1004ms rtt min/avg/max/mdev = 0.264/0.596/0.929/0.333 ms [root@gract1 ~]# nslookup ns1 Server: 192.168.1.50 Address: 192.168.1.50#53 Name: ns1.example.com Address: 192.168.5.50 To delete the above created route run : [root@gract1 ~]# ip route del 192.168.5.0/24 dev eth1