Verifying local network connectivity

The ping(ADMN) command sends TCP/IP packets to the desired destination and, if successful, returns packets to the sender. With ping, you can verify that the TCP/IP stack is configured correctly on the local host and that your system can reach others via configured interfaces. To verify connectivity:

• Enter ping localhost. This routes packets through the loopback mechanism, and should always succeed regardless of the state of your networking hardware or cabling. If it fails, use the Network Configuration Manager to reconfigure TCP/IP.

• Verify your network connections by using ping to try to contact one or more hosts on the local network that you know are running TCP/IP. For example, you might enter ping don.

• The command succeeds, and you see messages similar to:

     # ping don
     PING don (10.0.118.8): 56 data bytes
     64 bytes from don (10.0.118.8): icmp_seq=0 ttl=255 time=10 ms
     64 bytes from don (10.0.118.8): icmp_seq=1 ttl=255 time=10 ms
     64 bytes from don (10.0.118.8): icmp_seq=2 ttl=255 time=20 ms
     64 bytes from don (10.0.118.8): icmp_seq=3 ttl=255 time=10 ms
     64 bytes from don (10.0.118.8): icmp_seq=4 ttl=255 time=10 ms
     64 bytes from don (10.0.118.8): icmp_seq=5 ttl=255 time=20 ms
     64 bytes from don (10.0.118.8): icmp_seq=6 ttl=255 time=20 ms
     64 bytes from don (10.0.118.8): icmp_seq=7 ttl=255 time=10 ms
     64 bytes from don (10.0.118.8): icmp_seq=8 ttl=255 time=20 ms
     64 bytes from don (10.0.118.8): icmp_seq=9 ttl=255 time=20 ms
     
  
     --- don ping statistics ---
     10 packets transmitted, 10 packets received, 0% packet loss
     round-trip min/avg/max = 10/20/15 ms
  

• The command succeeds, but slowly and with packet loss. Check the network cabling on your system. On an Ethernet network, a loose cable tap or poorly placed power cable can result in severely deteriorated service.
  

• The command fails with the error message "hostname lookup failure". /etc/hosts may not have the correct permissions. Use the Software Manager's Verify feature to correct TCP/IP permissions problems.

  A hostname lookup failure may also indicate that a name server relied upon by your host is not running. Contact the administrator of the name server to verify that it is up and running, or see ``Configuring the Domain Name Service (DNS)'', for more information.

• The command hangs. You may need to fix interrupt conflicts or netmask/broadcast address problems.

  Use vectorsinuse(ADM) and hwconfig(C) to view the interrupt vectors already in use on your system. If your networking card's vector conflicts with that of another card, reconfigure your card with the Network Configuration Manager.

  Verify the netmask and broadcast address in use on your network by checking their values in /etc/tcp on another system. Look for a line or lines similar to the following:

     ifconfig net0 10.0.246.18 netmask 255.255.0.0  
     broadcast 10.0.255.255
  

  In this case, the network mask only masks the network portion of the address. Ensure that the values on your system match those of the other system, with the exception of the host portion of the interface address (in this case, 246.18).