Hitachi GR2000 Series User Manual

Page 205

Troubleshooting

GR2K-GA-0015

7-39

Ver. 07-02

7.5.2.2

Troubleshooting Communication Failures in DHCP Server

The following four factors may produce communication troubles in the DHCP server
(server unable to distribute an address to client):

1. Error in setting the configuration defining information.

2. Change in the network configuration.

3. Impediments in the DHCP server.

The procedure for dividing the impediment positions and causes is shown in the flow
shown below.

First, check No. 1 above. An explanation can be derived from the easily mistaken
“setting of configuration defining” information. Regarding No. 2 above, check the
network configuration for any differences before and after the change to discern if
there is any cause there hindering communication. If the client/server setting
(network card setting and cable connections) has been confirmed, but the case is still
such that “the IP address cannot be allocated to the clients and no IP communication
is possible although the configuration defining information and the network
configuration are correct” as shown in No. 3 above, the details on how to resolve this
issue are given in “(b) Inspection of Log Message and Interface” through “(e)
Inspection of FiItering/QoS Definition Information.”

Figure 7-13 DHCP Server Communication Failures Troubleshooting Chart

(a) Confirmation of Configuration Defining Information

It is possible that the IP addresses will not be allocated to clients if a mistake has
been made in setting the configuration definition for resources on the DHCP server.
The procedure for confirming the configuration defining information is given below.

Check for the configuration definition information

Check for any presence of physical failure with show

logging or show ip interface command.

No physical failure

(direct)

No physical

failure

(via relay agent)

Physical failure

Refer to Section 7.5.2.1,
“Troubleshooting DHCP/

BOOTP Relay Communication

Failures”