Install and configure dhcp server Ubuntu

This is a guide for Ubuntu dhcp server installation setup. DHCP is a Dynamic Host Configuration Protocol. By configuring a dhcp server, system administrator won't have to manually assign static ip address and other information for clients.

A traditional Linux dhcp server called dhcpd. However, a default Ubuntu server Hardy installation, you can no longer install dhcpd. There is no more dhcpd. Ubuntu Hardy or Intrepid only has these dhcp client and server packages:

dhcp-helper (0.7-2) [universe]
A DHCP relay agent
dhcp3-client (3.0.6.dfsg-1ubuntu9)
DHCP client
dhcp3-common (3.0.6.dfsg-1ubuntu9)
common files used by all the dhcp3* packages
dhcp3-relay (3.0.6.dfsg-1ubuntu9) [universe]
DHCP relay daemon
dhcp3-server (3.0.6.dfsg-1ubuntu9)
DHCP server for automatic IP address assignment
dhcp3-server
virtual package provided by udhcpd
dhcpcd (1:3.0.17-2) [universe]
DHCP client for automatically configuring IPv4 networking

Never mind, so we need to install dhcp3-server instead. Here we go:

[email protected]:~$ sudo apt-get install dhcp3-server
[sudo] password for luzar:
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
libdns32 libisc32
Use 'apt-get autoremove' to remove them.
The following NEW packages will be installed:
dhcp3-server
0 upgraded, 1 newly installed, 0 to remove and 2 not upgraded.
Need to get 318kB of archives.
After this operation, 774kB of additional disk space will be used.
Get:1 http://us.archive.ubuntu.com hardy/main dhcp3-server 3.0.6.dfsg-1ubuntu9 [318kB]
Fetched 318kB in 5s (61.2kB/s)
Preconfiguring packages ...
Selecting previously deselected package dhcp3-server.
(Reading database ... 18954 files and directories currently installed.)
Unpacking dhcp3-server (from .../dhcp3-server_3.0.6.dfsg-1ubuntu9_i386.deb) ...
Setting up dhcp3-server (3.0.6.dfsg-1ubuntu9) ...
Generating /etc/default/dhcp3-server...
* Starting DHCP server dhcpd3 [fail]
invoke-rc.d: initscript dhcp3-server, action "start" failed.

[email protected]:~$

Well, now we have Starting DHCP server dhcpd3 - Fail. Let's see what is the problem:

[email protected]:~$ tail /var/log/syslog
Nov 21 11:14:54 ubuntu dhcpd:
Nov 21 11:14:54 ubuntu dhcpd: No subnet declaration for eth0 (192.168.0.47).
Nov 21 11:14:54 ubuntu dhcpd: ** Ignoring requests on eth0. If this is not what
Nov 21 11:14:54 ubuntu dhcpd: you want, please write a subnet declaration
Nov 21 11:14:54 ubuntu dhcpd: in your dhcpd.conf file for the network segment
Nov 21 11:14:54 ubuntu dhcpd: to which interface eth0 is attached. **
Nov 21 11:14:54 ubuntu dhcpd:
Nov 21 11:14:54 ubuntu dhcpd:
Nov 21 11:14:54 ubuntu dhcpd: Not configured to listen on any interfaces!
Nov 21 11:17:01 ubuntu /USR/SBIN/CRON[4762]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
[email protected]:~$

So we haven't configure the dhcp configuration yet. Ok now let's configure the dhcp configuration file. The dhcp configuration file is /etc/dhcp3/dhcpd.conf. Below is the default ubuntu /etc/dhcp3/dhcpd.conf file:

#
# Sample configuration file for ISC dhcpd for Debian
#
# Attention: If /etc/ltsp/dhcpd.conf exists, that will be used as
# configuration file instead of this file.
#
# $Id: dhcpd.conf,v 1.1.1.1 2002/05/21 00:07:44 peloy Exp $
#

# The ddns-updates-style parameter controls whether or not the server will
# attempt to do a DNS update when a lease is confirmed. We default to the
# behavior of the version 2 packages ('none', since DHCP v2 didn't
# have support for DDNS.)
ddns-update-style none;

# option definitions common to all supported networks...
option domain-name "example.org";
option domain-name-servers ns1.example.org, ns2.example.org;

default-lease-time 600;
max-lease-time 7200;

# If this DHCP server is the official DHCP server for the local
# network, the authoritative directive should be uncommented.
#authoritative;

# Use this to send dhcp log messages to a different log file (you also
# have to hack syslog.conf to complete the redirection).
log-facility local7;

# No service will be given on this subnet, but declaring it helps the
# DHCP server to understand the network topology.

#subnet 10.152.187.0 netmask 255.255.255.0 {
#}

# This is a very basic subnet declaration.

#subnet 10.254.239.0 netmask 255.255.255.224 {
# range 10.254.239.10 10.254.239.20;
# option routers rtr-239-0-1.example.org, rtr-239-0-2.example.org;
#}

# This declaration allows BOOTP clients to get dynamic addresses,

# This declaration allows BOOTP clients to get dynamic addresses,
# which we don't really recommend.

#subnet 10.254.239.32 netmask 255.255.255.224 {
# range dynamic-bootp 10.254.239.40 10.254.239.60;
# option broadcast-address 10.254.239.31;
# option routers rtr-239-32-1.example.org;
#}

# A slightly different configuration for an internal subnet.
#subnet 10.5.5.0 netmask 255.255.255.224 {
# range 10.5.5.26 10.5.5.30;
# option domain-name-servers ns1.internal.example.org;
# option domain-name "internal.example.org";
# option routers 10.5.5.1;
# option broadcast-address 10.5.5.31;
# default-lease-time 600;
# max-lease-time 7200;
#}

# Hosts which require special configuration options can be listed in
# host statements. If no address is specified, the address will be
# allocated dynamically (if possible), but the host-specific information
# will still come from the host declaration.

#host passacaglia {
# hardware ethernet 0:0:c0:5d:bd:95;
# filename "vmunix.passacaglia";
# server-name "toccata.fugue.com";
#}

# Fixed IP addresses can also be specified for hosts. These addresses
# should not also be listed as being available for dynamic assignment.
# Hosts for which fixed IP addresses have been specified can boot using
# BOOTP or DHCP. Hosts for which no fixed address is specified can only
# be booted with DHCP, unless there is an address range on the subnet
# to which a BOOTP client is connected which has the dynamic-bootp flag
# set.
#host fantasia {
# hardware ethernet 08:00:07:26:c0:a5;
# fixed-address fantasia.fugue.com;
#}

# You can declare a class of clients and then do address allocation
# based on that. The example below shows a case where all clients
# in a certain class get addresses on the 10.17.224/24 subnet, and all
# other clients get addresses on the 10.0.29/24 subnet.

#class "foo" {
# match if substring (option vendor-class-identifier, 0, 4) = "SUNW";
#}

#shared-network 224-29 {
# subnet 10.17.224.0 netmask 255.255.255.0 {
# option routers rtr-224.example.org;
# }
# subnet 10.0.29.0 netmask 255.255.255.0 {
# option routers rtr-29.example.org;
# }
# pool {
# allow members of "foo";
# range 10.17.224.10 10.17.224.250;
# }
# pool {
# deny members of "foo";
# range 10.0.29.10 10.0.29.230;
# }
#}

Don't do anything to file yet. We need to backup the file in case something wrong happened. Use Linux cp command to duplicate the file like the example below:

[email protected]:~$ sudo cp /etc/dhcp3/dhcpd.conf /etc/dhcp3/dhcpd.conf.bak
[sudo] password for luzar:
[email protected]:~$

Now you can edit the file with your favorite text editor. Here is an example of a simple dhcpd.conf configuration for a local network:

# /etc/dhcp3/dhcpd.conf
#
#
ddns-update-style none;

# Lease time is in seconds
# Default lease is 1 week (604800 seconds)
default-lease-time 604800;
# Max lease is 4 weeks (2419200 seconds)
max-lease-time 2419200;

# If this DHCP server is the official DHCP server for the local
# network, the authoritative directive should be uncommented.
authoritative;

# All ip addresses and domain name are examples
subnet 192.168.0.0 netmask 255.255.255.0 {
option domain-name "example.com";
option broadcast-address 192.168.0.255;
option subnet-mask 255.255.255.0;
option domain-name-servers 192.168.0.47, 192.168.1.5; # Comma between domain
option routers 192.168.0.10;
range 192.168.0.20 192.168.0.50; # No comma, just whitespace
}

To make the dhcpd.conf configuration file above works for you, just change the domain name and related ip addresses. When you are done, restart dhcp3 service again. Here is the command:

[email protected]:~$ sudo /etc/init.d/dhcp3-server start
* Starting DHCP server dhcpd3 [ OK ]
[email protected]:~$

If you failed again, then there is something wrong with your dhcp.conf configuration. Normally, there is an error prompt that include detail about the error such as error name and error line. So, write that down, open dhcp configuration file again and fix the error. Also you can find the error in /var/log/messages and /var/log/daemon.log files. Use tail command to view latest error.

That's all. The Ubuntu dhcp server setup and configuration is complete. What's left is to configure client computers to use the server. For Windows client, here is a step by step instructions on how to setup dhcp client

Add new comment