HP Insight Control for Linux 6.0 User Guide

23.7 Troubleshooting DHCP problems
The following table describes possible causes of problems with Dynamic Host Configuration
Protocol (DHCP) and provides actions to correct them.
Corrective actionsCause/Symptom
Perform the appropriate action:
• Verify that the /etc/dhcpd.conf service
configuration file exists and that it is not empty.
• Verify that the /etc/dhcpd.conf service
configuration file is valid. Verify it against the output
of the examples in dhcpd.conf(5).
• Verify that DHCP is configured to serve IP address on
the correct network interface. Compare the output of
the ifconfig command (identify the correct interface)
and the contents of the /etc/sysconfig/dhcpd file.
• Start the DHCP service with the following command:
# /etc/init.d/dhcpd start
• Examine the /var/log/messages system log file for
error messages, and take any corrective action
required.
DHCP Process Not Running
The DHCP server process is absent from the process list,
verified with the following command:
# ps –ef | grep dhcp
Perform the appropriate action:
• Verify that the /etc/dhcpd.conf service
configuration file is valid. Verify it against the output
of the examples in dhcpd.conf(5).
• Verify that DHCP is configured to serve IP address on
the correct network interface. Compare the output of
the ifconfig command (identify the correct interface)
and the contents of the /etc/sysconfig/dhcpd file.
• Examine the /var/log/messages system log file for
error messages, and take any corrective action
required.
DHCP Process Will Not Start
Any attempt to start the DHCP process fails with errors.
• Verify that DHCP is configured to serve IP addresses
on the correct network interface. Compare the output
of the ifconfig command and the contents of the
/etc/sysconfig/dhcpd file to identify the correct
interface.
• Verify that the IPTables on the CMS does not block
DHCP requests. Either examine the IPTables rules to
ensure that the UDP ports 67 and 68 are allowed, or
turn the firewall off.
• Verify the /etc/dhcpd.conf file to verify that DHCP
is configured with sufficient IP addresses to supply
addresses for each of the managed systems, their
management processors, and onboard administrators.
• Examine the system log, /var/log/messages, for
error messages and take the required appropriate
action.
DHCP Process Runs But Does Not Provide IP Addresses
The DHCP process appears to run, verified with the
following command, but the clients on the network are
not receiving IP addresses.
# ps -ef | grep dhcp
226 Troubleshooting