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
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Never mind, so we need to install dhcp3-server instead. Here we go:
luzar@ubuntu:~$ 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. luzar@ubuntu:~$ |
Well, now we have Starting DHCP server dhcpd3 - Fail. Let's see what is the problem:
luzar@ubuntu:~$ 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)
luzar@ubuntu:~$
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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;
# }
#}
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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:
luzar@ubuntu:~$ sudo cp /etc/dhcp3/dhcpd.conf /etc/dhcp3/dhcpd.conf.bak
[sudo] password for luzar:
luzar@ubuntu:~$
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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
}
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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:
luzar@ubuntu:~$ sudo /etc/init.d/dhcp3-server start
* Starting DHCP server dhcpd3 [ OK ]
luzar@ubuntu:~$
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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
Information about changes for
Information about changes for 11.04 was helpful. thank you!
Great job with the tutorial.
Great job with the tutorial.
This is a very good
This is a very good information which helped me very much.
I have finally found out where stays dhcpd.conf file.
how can configure dhcp based
how can configure dhcp based on mac address..
This info was very helpful,
This info was very helpful, but with Ubuntu server 11.04 the directories/commands had changed to the following:
For associating an interface: /etc/default/isc-dhcp-server
To change the config file: /etc/dhcp/dhcpd.conf
To start the process: /etc/init.d/isc-dhcp-server start
Thanks for the information on
Thanks for the information on 11.04 changes. Very helpful.
Thanks so
Thanks so muuuuuuuuuccccccccchhhhhhhh!
I was looking for an solution to my problem for ages... and then i found your post... great thanks.
I was getting the Interface Problem "Not configured to listen on any interfaces!" and i was editing the wrong file!
Thanks again!!!
yeah dhcp works, but no
yeah dhcp works, but no internet, is there some routes or masquerading that also needs to be done on the server???
# Sample /etc/dhcpd.conf
# (add your comments here)
default-lease-time 600;
max-lease-time 7200;
option subnet-mask 255.255.255.0;
option broadcast-address 192.168.5.255;
option routers 192.168.5.1;
option domain-name-servers 192.168.5.1, 10.10.1.1;
option domain-name "ubuntu";
ddns-update-style none;
log-facility local7;
# dhcp0
subnet 192.168.5.0 netmask 255.255.255.0 {
authoritative;
range 192.168.5.2 192.168.5.30;
}
mine looks somewhat like
mine looks somewhat like this:
////////
ddns-update-style none;
# limit to serving dhcp requests on eth2
INTERFACES= "eth2";
default-lease-time 9600;
max-lease-time 19200;
authoritative;
log-facility local7;
subnet 10.0.0.0 netmask 255.0.0.0 {
range 10.0.0.1 10.0.0.220;
option broadcast-address 10.255.255.255;
option routers 10.0.0.254;
option netbios-name-servers 10.0.0.254;
option domain-name-servers 10.0.0.254;
}
////////
From what you've posted i can't see any issues with the dhcpd config (you have stuff in different places to me, but that shouldnt cause an issue)
Not sure why you have domain-name ubuntu, normally you would have an actually fqdn here, e.g example.com or you would have something line mynetwork.local - alternatively you just don't need it at all.
Possible issues:
1. you can access websites based on ip address, but not name - check that the dns servers are working and can resolve external names, alternatively substitute them for a pulic dns service e.g. google's on 8.8.8.8
2. you can't access any host that isn't on your local network - check that the router has the correct ip address and that the router actually 'routes' traffic (and has a default route to the internet) - if you want to use linux to route traffic look into iptables (iptables is also what you need if you want to NAT traffic)
what i have to do to make a
what i have to do to make a machine as dhcp relay agent..plz help me asap....
You can start dhcp3-server
You can start dhcp3-server at boot-up by adding a starting script in /etc/rc.d/rc.local:
You can read discussion in the Linuxquestions forum if you still have trouble starting the daemon at boot:
http://www.linuxquestions.org/questions/linux-networking-3/start-dhcpd-a...
and this thread would help you understand more:
http://www.linuxquestions.org/questions/linux-networking-3/how-to-start-...
How can I start DHCP3-Server
How can I start DHCP3-Server automatically or on boot-up?
Without having to type sudo /etc/init.d/dhcp3-server start
Hope you can answer this. Thanks.