LinuxQuestions.org - DHCP Server Question

Okay, I have been playing with this a little and decided to make a little script which could turn a little table into a complete dhcpd.conf file for use.

First the script:

Code:

#!/bin/sh

# Use this to parse a file of the following format to create a

# dhcpd.conf file for your network.

# Format of each line in the file:

# {macaddress}[,[ipaddress][,hostname]] 

# the things in []'s are optional.



HIGHBITS=10.0.0

NETMASK=255.255.255.0

BROADCAST=10.0.0.255

ROUTER=10.0.0.1

DOMAIN="foo.com"

NS="10.0.0.1, 65.0.0.4, 54.0.0.1"

HOSTNAME="host"

STARTNUM=2

HIGHNUM=22

ADDRESSFILE=~/tmp/macs.dat

OUTPUT=~/tmp/dhcpd.conf



header() 

{

        echo "deny unknown-clients;" > $OUTPUT

        echo "ddns-update-style ad-hoc;" >> $OUTPUT

        echo " " >> $OUTPUT

        echo "option routers ${ROUTER};" >> $OUTPUT

        echo "option broadcast-address ${BROADCAST};" >> $OUTPUT

        echo "option domain-name \"${DOMAIN}\";" >> $OUTPUT

        echo "option domain-name-servers ${NS};" >> $OUTPUT

        echo " " >> $OUTPUT

        echo "subnet ${HIGHBITS}.0 netmask ${NETMASK} {" >> $OUTPUT

        echo "range ${HIGHBITS}.${STARTNUM} ${HIGHBITS}.${HIGHNUM};" >> $OUTPUT

        echo "default-lease-time 604800;" >> $OUTPUT

        echo "max-lease-time 604800;" >> $OUTPUT

        echo "}" >> $OUTPUT

}



        



CURRENT=$STARTNUM

MACS=`cat ${ADDRESSFILE}`



header



for mac in $MACS

do

        macn=`echo $mac | awk 'BEGIN{FS=","}{print $1}'`

        ip=`echo $mac | awk 'BEGIN{FS=","}{print $2}'`

        host=`echo $mac | awk 'BEGIN{FS=","}{print $3}'`

        echo " " >> $OUTPUT

        if [ "x${host}" != "x" ]; then

                echo "host ${host} {" >> $OUTPUT

        else

                echo "host ${HOSTNAME}-${CURRENT} {" >> $OUTPUT

                CURRENT=`expr ${CURRENT} + 1`

        fi

        echo "hardware ethernet ${macn};" >> $OUTPUT

        if [ "x${ip}" != "x" ]; then

                echo "fixed-address ${ip};" >> $OUTPUT

        fi

        echo "}" >> $OUTPUT

done

Use this to parse a file which looks like this (using real numbers obviously):

Code:

ff:07:6b:32:d2:55,10.0.0.23,fnord

ff:0b:db:0d:a1:af

ff:03:47:b7:a9:ed,,laptop

ff:14:6c:00:bd:8b,10.0.0.2,wlan

ff:07:5b:ec:02:99,10.0.1.20

And it will produce this configuration file:

Code:

deny unknown-clients;

ddns-update-style ad-hoc;

 

option routers 10.0.0.1;

option broadcast-address 10.0.0.255;

option domain-name "foo.com";

option domain-name-servers 10.0.0.1, 65.0.0.4, 54.0.0.1;

 

subnet 10.0.0.0 netmask 255.255.255.0 {

range 10.0.0.2 10.0.0.22;

default-lease-time 604800;

max-lease-time 604800;

}

 

host fnord {

hardware ethernet ff:07:6b:32:d2:55;

fixed-address 10.0.0.23;

}

 

host host-2 {

hardware ethernet ff:0b:db:0d:a1:af;

}

 

host laptop {

hardware ethernet ff:03:47:b7:a9:ed;

}

 

host wlan {

hardware ethernet ff:14:6c:00:bd:8b;

fixed-address 10.0.0.2;

}

 

host host-3 {

hardware ethernet ff:07:5b:ec:02:99;

fixed-address 10.0.1.20;

}

Note: This is setup to automatically deny any client which has an unknown mac address (it's in the deny line). If you look at the lines in the mac address file you can see pretty much how to setup whatever you want.

Any other changes you would make or differences you want can be done by just editing the script for your needs.