Nextelco:DHCP

DHCP server

For DHCP service implementation isc dhcp server has been used. These are the steps followed for its installation and configuration:

1. Install isc-dhcp-server

# apt-get install isc-dhcp-server

2. After the installation the server is not able to run automatically, these are the error messages thrown to syslog

appserver dhcpd: Internet Systems Consortium DHCP Server 4.2.2
appserver dhcpd: Copyright 2004-2011 Internet Systems Consortium.
appserver dhcpd: All rights reserved.
appserver dhcpd: For info, please visit https://www.isc.org/software/dhcp/
appserver dhcpd: Internet Systems Consortium DHCP Server 4.2.2
appserver dhcpd: Copyright 2004-2011 Internet Systems Consortium.
appserver dhcpd: All rights reserved.
appserver dhcpd: For info, please visit https://www.isc.org/software/dhcp/
appserver dhcpd: Wrote 0 leases to leases file.
appserver dhcpd: 
appserver dhcpd: No subnet declaration for eth1 (192.168.14.4).
appserver dhcpd: ** Ignoring requests on eth1.  If this is not what
appserver dhcpd:    you want, please write a subnet declaration
appserver dhcpd:    in your dhcpd.conf file for the network segment
appserver dhcpd:    to which interface eth1 is attached. **
appserver dhcpd: 
appserver dhcpd: 
appserver dhcpd: Not configured to listen on any interfaces!

3. Edit /etc/dhcp/dhcpd.conf file and set the following configuration

#
# Sample configuration file for ISC dhcpd for Debian
#
#

# The ddns-updates-style parameter controls whether or not the server will
# attempt to do a DNS update when a lease is confirmed. We default to the
# behavior of the version 2 packages ('none', since DHCP v2 didn't
# have support for DDNS.)
ddns-update-style none;

# option definitions common to all supported networks...
option domain-name "basicinternet.no";
option domain-name-servers 192.168.14.4;

default-lease-time 600;
max-lease-time 7200;

# 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.

host config {
       hardware ethernet 00:26:08:0d:b2:e6;
       fixed-address 192.168.14.10;
}


subnet 192.168.14.0 netmask 255.255.255.0 {
       range 192.168.14.100 192.168.14.200;
       option routers 192.168.14.1;
       option domain-name-servers 192.168.14.4;
       option broadcast-address 192.168.14.255;
       option domain-name "basicinternet.no";
       default-lease-time 600;
       max-lease-time 7200;
}


#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;
#}

# 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;
#  }
#}

4. Finally, if we want to check which are the IP addresses the server has leased, we use the following command

#more /var/lib/dhcp/dhcpd.leases

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