DHCP SERVER on RHEL 6

DHCP SERVER ON REDHAT 6

lab scenario := 
server IP =192.168.0.10
server Hostname = server.example.com
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1st step := Install dhcp package 
# yum -y install dhcp* 
then 
2nd step := copy the dhcpd.sample.conf file 
# cp /usr/share/doc/dhcp-4.1.1/dhcpd.conf.sample /etc/dhcp/dhcpd.conf
 
3rd step := edit the dhcpd.conf below like this
# dhcpd.conf

#

# Sample configuration file for ISC dhcpd

#



# 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;



# Use this to enble / disable dynamic dns updates globally.

#ddns-update-style none;



# 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,

# 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;

#}



subnet 192.168.0.0 netmask 255.255.255.0 {

  range 192.168.0.80 192.168.0.100;

  option domain-name-servers server.example.com;

  option domain-name "server.example.com";

  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;

  }

}

 save and quit 

and start the service 
# /etc/init.d/dhcpd start