Clients Unable To Receive A Dhcp Address - HP ProCurve Secure 7000dl Series Basic Management And Configuration Manual

Dynamic Host Configuration Protocol (DHCP)
Managing and Troubleshooting the DHCP Server
C a u t i o n
13-20
Debug messages can tie up the router's processor. Therefore, you should be
very cautious about using them in a live network. You should begin by
troubleshooting the host experiencing the problem and rule out a connectivity
problem.
In a large network, you should not use DHCP debug messages to fix a problem
for a single host. The router may be flooded with DHCP messages from other
hosts, and displaying them all could potentially compromise network
performance.
DHCP messages generally break down into the steps of the DHCP request
process. You can look for a message that repeats several times to determine
where the process begins to break down.
View Table 13-1 for a quick guide to what steps you should take when you see
a debug message repeat again and again.
Table 13-1. DHCP Debug Messages
Repeated Message
Processing Discover
message
Server sent an Offer to the
Client

Clients Unable to Receive a DHCP Address

If the router continually receives the "Processing Discover Message" event, it
is having difficulty preparing an offer for the client. One of the most common
reasons for this difficulty is that the server cannot find an available IP address.
It is possible that all available addresses are being used (view the DHCP client
bindings by entering show ip dhcp-server binding). However, it could be
that the default router for the pool is not on the same subnet as the network
address, which prevents the router from finding a valid IP address.
View the running-config (show run) and look for the DHCP pool for the clients
unable to get an address. This is the pool whose default router is the interface
to which the client connects. The address for the network should match the
network bits in the default router address.
Possible Problem
• There are no addresses
available.
• The default gateway is on
the wrong subnet.
The client will not accept the
address and configurations.
Best Next Step
• Check the DHCP client
bindings.
• Check settings for the
pool.
Troubleshoot the host.