NEC IP8800/S2400 Series Troubleshooting Manual page 117

(a) Checking the log and interface
On possible cause for the server not assigning IP addresses to clients, communication between client and server may
have been disabled. Check the log displayed on this system or the interface up/down status using the show ip
interface command. For the procedure, see
(b) 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. Use the ping command to check communication between both parties. For an example of issuing ping and how
to interpret the result, see the manual "Configuration Settings."
3. If communication to the other party cannot be verified with the ping command, use the ping command to check
communication to remote systems starting from the system closest to this system.
4. If the result of the ping command shows that the neighboring system has failed, go to
information with neighboring
information."
(c) Identifying the extent of failure (performed from the customer's terminal equipment)
If login to this system is not possible, follow the procedure below to identify the extent of failure to see the failure
location in the route between the customer's terminal equipment and the other party.
1. Confirm that the customer's terminal equipment has the ping function.
2. Use the ping function to check communication between the customer's terminal equipment and the remote system.
3. If communication to the remote system cannot be verified with the ping command, use ping again to check
communication to systems starting from the system closest to the customer's terminal equipment.
4. After the extent of failure has been identified using the ping command, log in to this system if it is considered to
have failed and follow the failure analysis flow to check for the failure cause.
(d) Checking ARP resolution information with neighboring system
If communication with a neighboring system is not possible as a result of ping execution, address resolution by ARP
may not have been achieved. The procedure for checking the status of address resolution between this system and the
neighboring system is described below.
1. Log in to the system.
2. Use the show ip arp command to check the status of address resolution status with the neighboring system
(presence/ absence of ARP entry information).
3. If the address resolution with the neighboring system is achieved (ARP entry information is provided), go to
"(e)Checking route information."
4. Confirm that the IP network setting can be exchanged between the neighboring system and this system if the address
resolution with the neighboring system is not achieved (ARP entry information is not provided).
(e) Checking route information
Check the route information acquired by this system if the following happens: Communication is not possible even
when the address resolution with the neighboring system is achieved, communication is disabled in the midway to the
other party, or the route to the other party is abnormal.
Take the following procedure.
1. Log in to the system.
"3.6.1 Communication Is Disabled or Is
system." If the result shows that the remote system has failed, go to
3.
Troubleshooting Functional Failures in Operation
Disconnected."
"(d)Checking ARP resolution
"(e)Checking route
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