Hướng dẫn cài đặt và cấu hình DHCP trên Linux

# wget ftp://ftp.isc.org/isc/dhcp/dhcp-4.2.2.tar.gz

# tar -xvf dhcp-4.2.2.tar.gz

# cd dhcp-4.2.2

# ./configure

# make

# make install

# cp /usr/local/etc/dhcpd.conf /etc/

#vi /etc/dhcpd.conf

option domain-name "sinhvienit.net";
option domain-name-servers 192.168.1.1,8.8.8.8;


default-lease-time 600; 
# Thời gian mặc định cho client giữ IP đc cấp
max-lease-time 7200;  
# Thời gian tối đa cho client giữ IP đc cấp

subnet 192.168.1.0 netmask 255.255.255.0 {


# Dải cấp phát là 192.168.1.50 đến 192.168.1.100, 
# có thể thêm nhiều dải khác bằng cách thêm nhiều dòng
  range 192.168.1.50 192.168.1.100;


# có thể không cấu hình 4 dòng dưới 
# vì giống cấu hình mặc định ở (*1)
  option domain-name-servers 192.168.1.2,8.8.8.8;
  option domain-name "sinhvienit.net";
  default-lease-time 600;
  max-lease-time 7200;


# default gateway mà Client sẽ sử dụng
  option routers 192.168.1.1; 
# Địa chỉ Broadcast của mạng con
  option broadcast-address 192.168.1.255; 
}

host MyPC {
  hardware ethernet 08:00:07:26:c0:a5;
  fixed-address 192.168.1.55;
}

# touch /var/db/dhcp.leases

# cat /dev/null > /var/db/dhcp.leases

# /usr/local/sbin/dhcpd

# killproc dhcpd

# ps –A|grep dhcpd

# chckconfig --level 35 dhcpd on

# netstat -npl|grep dhcp

# cat /var/db/dhcpd.leases

ipconfig    /release

ipconfig    /renew

# vi /etc/init.d/dhcpd

#!/bin/sh
#
# dhcpd        Init Script to start/stop dhcpd.
#
# chkconfig:    - 61 39
# description:    If you dont know you shouldnt be here
#
# processname: dhcpd
config_file=/etc/dhcpd.conf
pidfile=/var/run/dhcpd.pid
lease_file=/var/db/dhcpd.leases




# Source function library
. /etc/rc.d/init.d/functions


# Get network config
. /etc/sysconfig/network


  if [ ! -e $config_file ]; then
    echo " No config file at $config_file"
    exit 0
  fi


RETVAL=0


start() {
  if [ ! -e $lease_file ]; then
        echo "  Creating $lease_file"
        touch $lease_file


  elif [ -f $pidfile ]; then
        PID=`cat $pidfile`
        echo "    ISC-DHCPD already running: $PID"
        exit 2;
  else
    echo -n $"Starting ISC-DHCPD: "
    daemon /usr/local/sbin/dhcpd -q 
    RETVAL=$?
    echo
    [ $RETVAL -eq 0 ] && touch /var/lock/subsys/dhcpd        
    return $RETVAL
  fi
}


stop() {
    echo -n $"Stopping ISC-DHCPD: "
    killproc dhcpd
    RETVAL=$?
    echo
[ $RETVAL -eq 0 ] && rm -f /var/run/dhcpd.pid /var/lock/subsys/dhcpd
    return $RETVAL
}


restart() {
    stop
    start
}


reload() {
        echo -n $"Reloading dhcpd: "
        killproc dhcpd -USR2
        RETVAL=$?
        echo
        return $RETVAL
}




case "$1" in
  start)
    start
    ;;
  stop)
    stop
    ;;
  status)
    status dhcpd
    ;;
  restart)
    restart
    ;;
  condrestart)
    [ -f /var/lock/subsys/dhcpd ] && restart || :
    ;;
  reload)
    reload
    ;;
  *)
    echo $"Usage: $0 {start|stop|status|restart|condrestart|reload}"
    exit 1
esac


exit $?

#chmod 755 /etc/init.d/dhcpd

# service dhcpd start

# service dhcpd stop

# service dhcpd restart

# service dhcpd status