Installing and Administering Internet Services

Chapter 6 275
Dynamic Host Configuration Protocol (DHCP)
Monitoring and Troubleshooting DHCP Operations
Monitoring and Troubleshooting DHCP
Operations
This section describes techniques and tools you can use to troubleshoot
problems found with the DHCP server.
Troubleshooting Techniques
You can use one of four techniques for monitoring DHCP:
• Syslog with debugging turned up
• Trace DHCP packets flowing in and out
• Dump the internal state of the daemon
• Review the contents of /etc/dhcpdb
Using Syslog with Debugging Turned On
Syslog collects the most detailed information about operations. You will
get the most direct, real-time information when you use syslog. However,
this method is only good for monitoring short periods of time because
syslog grows quickly.
1. Open the /etc/inetd.conf file in an editor.
2. Insert the -d3 option in the bootp line in the /etc/inetd.conf file.
bootps dgram udp wait root /usr/lbin/bootpd bootpd -d3
3. Reconfigure inetd with inetd -c.
a. Type inetd -c on the command line.
b. Terminate bootpd. The next time bootp comes up, the new
command line option will be available.
4. Tail the syslog by typing the following command:
tail -f /var/adm/syslog/syslog.log | grep bootp
You should be looking for the following:
• Is the client request reaching the server at all?
• Does the server make a reply to the client?