Red Hat Enterprise Linux 5 Administration Unleashed

Summary 325This argument is useful for a DHCP server with separate network cards for traffic insideand outside a private network. For security reasons, the DHCP server should only listenfor client connections on the NIC configured for internal traffic.Additional command-line options are explained in the man page for dhcpd. Use thecommand man dhcpd to read it.Logging ConnectionsBy default, log messages from the DHCP server are written to /var/log/messages.However, DHCP supports logging to a separate file by adding the following statement tothe top of dhcpd.conf:log-facility ;For example, to use the local7 facility of syslog, use the following line:14log-facility local7;The /etc/syslog.conf file must also be modified to include the following:#Log DHCP daemon messages to separate filelocal7.*/var/log/dhcpd.logYou can use a different name for the log file, but the syslog.conf line must include itsfull path and it must be created with the same permissions as the /var/log/messages file.Also restart syslog to enable the change (as the root user):service syslog restartBecause the log-facility statement is not read until dhcpd.conf is read, all logs beforereading the configuration file are still written to /var/log/messages.For more details on log facilities, refer to the syslog and syslog.conf man pages.SummaryWhen configuring a large network of systems, DHCP can be used to quickly and easilyconfigure client network settings. Clients can be assigned a specific IP address based onthe MAC addresses of their network cards or can be assigned a random IP address from adefined range. Administrators benefit from this configuration because changes can bemade on a central server instead of on each individual client.For more information, refer to the dhcpd and dhcpd.conf man pages with the commandsman dhcpd and man dhcpd.conf. For a complete list of DHCP options, use the commandman dhcp-options.