DHCP
安装
yum install -y dhcp
配置文件
默认配置为/etc/dhcpd.conf
[root@samba ~]# [root@samba ~]# rpm -ql dhcp | grep conf.sample /usr/share/doc/dhcp-3.0.5/dhcpd.conf.sample [root@samba ~]#
使用此示例配置文件覆盖/etc/dhcpd.conf
根据具体情况配置此文件
[root@samba ~]# cat /etc/dhcpd.conf
ddns-update-style interim;
ignore client-updates;
subnet 100.1.1.0 netmask 255.255.255.0 {
# --- default gateway
option routers 100.1.1.1;
option subnet-mask 255.255.255.0;
option nis-domain "domain.org";
option domain-name "domain.org";
option domain-name-servers 114.114.114.114;
option time-offset -18000; # Eastern Standard Time
# option ntp-servers 192.168.1.1;
# option netbios-name-servers 192.168.1.1;
# --- Selects point-to-point node (default is hybrid). Don't change this unless
# -- you understand Netbios very well
# option netbios-node-type 2;
range dynamic-bootp 100.1.1.128 100.1.1.254;
default-lease-time 21600;
max-lease-time 43200;
# we want the nameserver to appear at a fixed address
host ns {
next-server marvin.redhat.com;
hardware ethernet 12:34:56:78:AB:CD;
fixed-address 207.175.42.254;
}
}
关于配置文件内容跟参数选项意义参考一下：
/etc/dhcpd.conf通常包括三部分：parameters、declarations 、option。
1.DHCP配置文件中的parameters（参数）：表明如何执行任务，是否要执行任务，或将哪些网络配置选项发送给客户。主要内容见表1
2. DHCP配置文件中的declarations （声明）：用来描述网络布局、提供客户的IP地址等。主要内容见表2：
3. DHCP配置文件中的option（选项）：用来配置DHCP可选参数，全部用option关键字作为开始，主要内容包括见表3：
注意：如果客户端使用的是视窗操作系统，不要选择"host-name"选项，即不要为其指定主机名称。
启动服务
service dhcpd start
或者
dhcpd -p 67 -cf /etc/dhcpd.conf
查看端口是否监听
netstat -an | grep 67
启动脚本，可以查看很多相关记录文件信息
#!/bin/sh
#
### BEGIN INIT INFO
# Provides: dhcpd
# Default-Start:
# Default-Stop:
# Should-Start:
# Required-Start: $network
# Required-Stop:
# Short-Description: Start and stop the DHCP server
# Description: dhcpd provides the Dynamic Host Configuration Protocol (DHCP)
# server.
### END INIT INFO
#
# The fields below are left around for legacy tools (will remove later).
#
# chkconfig: - 65 35
# description: dhcpd provides the Dynamic Host Configuration Protocol (DHCP) \
# server
# processname: dhcpd
# config: /etc/dhcpd.conf
# config: /var/lib/dhcpd/dhcpd.leases
# pidfile: /var/run/dhcpd.pid
. /etc/rc.d/init.d/functions
RETVAL=0
prog=dhcpd
exec=/usr/sbin/dhcpd
lockfile=/var/lock/subsys/dhcpd
pidfile=/var/run/dhcpd.pid
statedir=/var/lib/dhcpd
[ -f /etc/sysconfig/dhcpd ] && . /etc/sysconfig/dhcpd
# if the user specified a different config file, make sure we reference it
findConfig() {
for arg in $DHCPDARGS ; do
if [ "$found" = 1 ]; then
[ -f "$arg" ] && echo "$arg"
return
fi
if [ "$arg" = "-cf" ]; then
found=1
continue
fi
done
echo "/etc/dhcpd.conf"
}
config="$(findConfig "$DHCPDARGS")"
if [ ! -f $statedir/dhcpd.leases ] ; then
mkdir -p $statedir
touch $statedir/dhcpd.leases
[ -x /sbin/restorecon ] && [ -d /selinux ] && /sbin/restorecon $statedir/dhcpd.leases >/dev/null 2>&1
fi
configtest() {
[ -x $exec ] || return 5
[ -f $config ] || return 6
$exec -q -t -cf $config
RETVAL=$?
if [ $RETVAL -eq 1 ]; then
$exec -t -cf $config
else
echo "Syntax: OK" >&2
fi
return $RETVAL
}
rh_status() {
status -p $pidfile $exec
}
rh_status_q() {
rh_status >/dev/null 2>&1
}
start() {
[ `id -u` -eq 0 ] || return 4
[ -x $exec ] || return 5
[ -f $config ] || return 6
rh_status_q && return 0
echo -n $"Starting $prog: "
daemon --pidfile=$pidfile $exec $DHCPDARGS 2>/dev/null
RETVAL=$?
echo
[ $RETVAL -eq 0 ] && touch $lockfile
return $RETVAL
}
stop() {
[ `id -u` -eq 0 ] || return 4
rh_status_q || return 0
echo -n $"Shutting down $prog: "
killproc -p $pidfile $prog
RETVAL=$?
echo
[ $RETVAL -eq 0 ] && rm -f $lockfile
return $RETVAL
}
usage() {
echo $"Usage: $0 {start|stop|restart|force-reload|condrestart|try-restart|configtest|status}"
}
if [ $# -gt 1 ]; then
exit 2
fi
case "$1" in
start)
start
;;
stop)
stop
;;
restart|force-reload)
stop ; start
;;
condrestart|try-restart)
rh_status_q || exit 0
stop ; start
;;
reload)
usage
# unimplemented feature
exit 3
;;
configtest)
configtest
;;
status)
rh_status
;;
*)
usage
exit 2
;;
esac
exit $?
服务端查看已分配的IP地址
客户端的重新获取都会得到记录
[root@samba ~]#
[root@samba ~]#
[root@samba ~]# cat /var/lib/dhcpd/dhcpd.leases
# All times in this file are in UTC (GMT), not your local timezone. This is
# not a bug, so please don't ask about it. There is no portable way to
# store leases in the local timezone, so please don't request this as a
# feature. If this is inconvenient or confusing to you, we sincerely
# apologize. Seriously, though - don't ask.
# The format of this file is documented in the dhcpd.leases(5) manual page.
# This lease file was written by isc-dhcp-V3.0.5-RedHat
lease 100.1.1.254 {
starts 4 2016/05/05 03:41:36;
ends 4 2016/05/05 09:41:36;
binding state active;
next binding state free;
hardware ethernet 00:0c:29:30:b2:b3;
}
lease 100.1.1.254 {
starts 4 2016/05/05 04:12:03;
ends 4 2016/05/05 10:12:03;
binding state active;
next binding state free;
hardware ethernet 00:0c:29:30:b2:b3;
}
客户端查看相关信息
客户端上获取到IP地址后，dhclient 可以查看下相关信息，比如dhcp server等
[root@localhost ~]# [root@localhost ~]# pkill dhclient [root@localhost ~]# dhclient Internet Systems Consortium DHCP Client V3.0.5-RedHat Copyright 2004-2006 Internet Systems Consortium. All rights reserved. For info, please visit http://www.isc.org/sw/dhcp/ Listening on LPF/eth0/00:0c:29:30:b2:b3 Sending on LPF/eth0/00:0c:29:30:b2:b3 Sending on Socket/fallback DHCPREQUEST on eth0 to 255.255.255.255 port 67 (xid=0x6656d649) DHCPACK from 100.1.1.100 (xid=0x6656d649) bound to 100.1.1.254 -- renewal in 8131 seconds. [root@localhost ~]# [root@localhost ~]#
如果想查看更详细的信息，例如租期等等，可查看相关文件
[root@localhost ~]# ls /var/lib/dhclient/
dhclient-eth0.leases dhclient.leases
[root@localhost ~]#
[root@localhost ~]# cat /var/lib/dhclient/dhclient.leases
lease {
interface "eth0";
fixed-address 100.1.1.254;
option subnet-mask 255.255.255.0;
option time-offset -18000;
option dhcp-lease-time 21600;
option routers 100.1.1.1;
option dhcp-message-type 5;
option dhcp-server-identifier 100.1.1.100;
option domain-name-servers 114.114.114.114;
option nis-domain "domain.org";
option domain-name "domain.org";
renew 4 2016/5/5 20:28:53;
rebind 4 2016/5/5 23:11:17;
expire 4 2016/5/5 23:56:17;
}
lease {
interface "eth0";
fixed-address 100.1.1.254;
option subnet-mask 255.255.255.0;
option time-offset -18000;
option routers 100.1.1.1;
option dhcp-lease-time 21600;
option dhcp-message-type 5;
option domain-name-servers 114.114.114.114;
option dhcp-server-identifier 100.1.1.100;
option nis-domain "domain.org";
option domain-name "domain.org";
renew 4 2016/5/5 20:12:29;
rebind 4 2016/5/5 23:11:58;
expire 4 2016/5/5 23:56:58;
}
本文出自 “逆行者” 博客，谢绝转载！