Introduction to DHCP
The DHCP package contains both the
client and server programs for DHCP. dhclient (the client) is useful
for connecting your computer to a network which uses DHCP to assign
network addresses. dhcpd (the server) is useful for
assigning network addresses on your private network.
This package is known to build and work properly using an LFS-7.0
platform.
Package Information
Additional Downloads
DHCP Dependencies
Required
Net-tools-1.60 is required at runtime by
dhclient if you do
not use the iproute2 patch.
User Notes: http://wiki.linuxfromscratch.org/blfs/wiki/dhcp
Installation of DHCP
If you have not compiled IPv6 support into the kernel, apply the
missing_ipv6 patch
patch -Np1 -i ../dhcp-4.2.3-missing_ipv6-1.patch
If you are installing the client, apply the iproute2 patch unless
you will have installed net-tools
by the time you wish to use the client:
patch -Np1 -i ../dhcp-4.2.3-iproute2-1.patch
Install DHCP by running the
following commands:
sed -i 's%\(^sbindir =\).*%\1 @prefix@@sbindir@%' server/Makefile.in &&
./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var \
--sbindir=/sbin \
--with-srv-lease-file=/var/state/dhcp/dhcpd.leases \
--with-srv6-lease-file=/var/state/dhcp/dhcpd6.leases \
--with-cli-lease-file=/var/state/dhclient.leases \
--with-cli6-lease-file=/var/state/dhclient6.leases &&
sed -i 's/-Werror//' {client,common,dst,omapip,relay,server,tests}/Makefile
If you only wish to build the server, enter:
sed -i 's/ client//' Makefile
If you only wish to build the client, enter:
sed -i 's/ dhcpctl relay server//' Makefile
Build your chosen variant(s) with:
make
To test the results, issue: make
check
Now, as the root user:
make install
The supplied /etc/dhcpd.conf (server)
and /etc/dhclient.conf (client) are
examples for a specific BSD system.
They are unlikely to be appropriate to your needs, but you may wish
to read them for ideas before deleting them or moving them to a
different location.
Now create the director(y,ies) for the leases.
For the server:
mkdir -pv /var/state/dhcp
For the client:
mkdir -pv /var/state
Command Explanations
sed -i 's%\(^sbindir =\).*%\1
@prefix@@sbindir@%' server/Makefile.in This command
moves the dhcp
program to /usr/sbin instead of
/sbin because it is not needed while
the server is booting.
--sbindir=/sbin The
dhclient program is
moved to /sbin instead of
/usr/sbin so that it is available
during boot, e.g. if /usr is to be an
nfs mount.
--with-*-lease-files=... By
default, lease files are placed in /var/db which is an anachronism.
sed -i 's/-Werror//'
{client,common,...}/Makefile - the Makefiles in
this package add -Werror to the
CFLAGS. On recent versions of
gcc more things, particularly
unused variables, create warnings. The -Werror flag causes warnings to break the build,
so we remove it where necessary.
sed -i 's/ something//'
Makefile - this stops the build from entering the
director(y,ies) named here.
rm -v /usr/lib/lib{dhcpctl,dst,omapi}.a
- there is no easy way to prevent these static libraries being
installed, but they are only needed during the build of this
package. libdhcpctl.a is only
installed if you build the server.
Configuring DHCP
Config Files
/etc/dhclient.conf and /etc/dhcpd.conf
Configuration Information
Information on configuring the DHCP client can be found in
Chapter 13,
Connecting to a Network.
Note that you only need the DHCP server if you want to issue LAN
addresses over your network. The DHCP client doesn't need this
script to be used. Also note that this script is coded for the
eth1 interface,
which may need to be modified for your hardware configuration.
Install the /etc/rc.d/init.d/dhcp
init script included in the blfs-bootscripts-20111226 package.
make install-dhcp
The lease file must exist on startup. The following command will
satisfy that requirement:
touch /var/state/dhcp/dhcpd.leases
The following commands will create a base configuration file for
a DHCP server. There are several options that you may want to add
(information that is passed back to the DHCP client) and those
are covered in the man pages for dhcp.conf.
cat > /etc/dhcpd.conf << "EOF"
default-lease-time 72000;
max-lease-time 144000;
subnet <192.168.5.0> netmask <255.255.255.0> {
range <192.168.5.10> <192.168.5.240>;
option broadcast-address <192.168.5.255>;
option routers <192.168.5.1>;
}
EOF
All addresses should be changed to meet your circumstance.