SLAC CPE Software Engineering Group
Programmers' Guides, Users' Guides
DHCP, Dynamic Host Configuration Protocal, implemented via dhcpd, automatically assigns IP and other network configuration information (subnet mask, broadcast address) to computers on a network. IP addresses are either dynamically assigned from a range, or statically assigned by MAC address. A DHCP client will send out a broadcast request to the DHCP server requesting an address. The DHCP server will then issue a "lease" and assign it to that client. DHCP, a superset of BOOTP, provides service to both DHCP cleint and BOOTP cleints. DHCP reduces the ammount of time required to configure clients and allows one to move a computer to various networks and be configured with the appropriate IP address, gateway and subnet mask
How to update DHCP service
[root@lcls-srv20 ~]# rpm -qa | grep dhcp
DHCP daemon Setup
/sbin/chkconfig --list dhcpd
/sbin/chkconfig dhcpd on
service dhcpd restart
DHCP Server Configuration
dhcpd, DHCP daemon, is configured in /etc/dhcpd.conf. A leases file is kept in /var/lib/dhcp/dhcpd.leases.
[root@mccsrv01 ~]# cat /etc/dhcpd.conf
#Required for dhcp 3.0+ / RHEL4 +. Otherwise, dhcpd wont start.
# default DNS to be used by DHCP clients
option domain-name-servers mcc-pep.slac.stanford.edu, mccdev-pep.slac.stanford.edu;
# default gateway to be used by DHCP clients
option routers 172.19.55.1;
# default subnet mask to be used by DHCP clients
# default broadcast address to be used by DHCP clients
... more exmaples with comments...
The configuration file is visible to the public via
DHCP Client Configuration
.... make entry here...
First, test configuration file for syntax errors with the following command:
service dhcpd configtest -while monitoring /var/log/messages ( tail –f /var/log/messages ) for any error messages. It is important to test the configuration file if there is any change made, before restart dhcpd.
When dhcpd is running it will generate entries in the file: /var/lib/dhcp/dhcpd.leases
tail –f /var/log/messages | grep mccsrv
Backup of dhcpd.conf
Ken's Original Note
Test config on mccsrv01
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Created by: Ken Brobeck 14-May-2010