bash$ ping 1.2.3.1 -c 3 PING 1.2.3.1 (1.2.3.1) from 1.2.3.4 : 56(84) bytes of data. Warning: time of day goes back, taking countermeasures. 64 bytes from 1.2.3.1: icmp_seq=0 ttl=255 time=5.691 msec 64 bytes from 1.2.3.1: icmp_seq=1 ttl=255 time=493 usec 64 bytes from 1.2.3.1: icmp_seq=2 ttl=255 time=487 usec --- 1.2.3.1 ping statistics --- 3 packets transmitted, 3 packets received, 0% packet loss round-trip min/avg/max/mdev = 0.487/2.223/5.691/2.452 ms
If your gateway was 1.2.3.1 and you got results like the results above then that means that everything is working right. If you cannot ping the gateway you will get results that look a little bit like this.
bash$ ping 1.2.3.1 -c 3 PING 1.2.3.1 (1.2.3.1) from 1.2.3.4 : 56(84) bytes of data. From 1.2.3.4: Destination Host Unreachable From 1.2.3.4: Destination Host Unreachable From 1.2.3.4: Destination Host Unreachable --- 1.2.3.1 ping statistics --- 3 packets transmitted, 0 packets received, +3 errors, 100% packet loss
If the gateway is unreachable you need see if other computers on the same network can talk to the gateway. If they can talk to the gateway, but you cannot, see if you can talk to them. It is possible that you are not on the same network, or that your netmask is not the same as theirs. Everyone on the network should have the same network mask.