NEC IP8800/S2400, IP8800/S6600, IP8800/S3600, IP8800/S6700, IP8800/S6300 Checking route information

3.Troubleshooting Functional Failures in Operation

(d) Identifying the extent of the failure (performed from this system)

If no failure is found on this system, a failure may exist somewhere in the route between this system and the remote system. The procedure to locate the failure in the route to the remote system and identify the failure range is as follows:

1.Log in to the system.

2.If a router is provided between the DNS server and DHCP server, use the ping command to verify communication of the system (router) between the DHCP server and the other system (DNS server) to which communication is disabled. If communication to the other party cannot be verified with the ping command, use ping to check communication toward clients starting from the system closest to this system. For an example of issuing ping and how to interpret the result, see the manual "Configuration Settings."

3.If the DNS server and DHCP server are directly connected, check the HUB and cable connections.

4.Depending on the extent of failure detected by the ping command, that is the neighboring system or remote system, proceed to the next step in the failure analysis flow.

(e) Checking route information

Check the route information acquired by this system if communication is not possible even when the address resolution with the neighboring system is achieved, or if communication is disabled in the midway to the other party, or if the route to the other party is abnormal. Use the following procedure:

1.Log in to the system.

2.Execute the show ip route command to check the route information acquired by this system.

(f)Checking filtering/QoS setting information

Only certain packets may have been discarded by filtering, or packets may have been discarded through bandwidth monitoring, discarding control, or shaper of the QoS control.

Check to see if the conditions of filtering and QoS control in the configuration have been set up correctly and if bandwidth monitoring, discarding control, or shaper has been set up appropriately for system operation in system configuration, on this system and on the relay equipment located between the DNS server and DHCP server. For the procedure, see "3.23.1 Checking Filtering/QoS Setting Information."

(g) Checking layer 2 network

If no setting error or failure is found in steps (a) to (f), the layer 2 network may have problem. Check the layer 2 network, referring to "3.5 Layer 2 Network Communication Failure."

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