

	Upgrading to dnsmasq V2
        -----------------------

Version 1.x of dnsmasq includes a facility for reading the dhcp.leases
file written by ISC dhcpd. This allows the names of machines which
have addresses allocated by DHCP to be included in the DNS.

Version 2.x of dnsmasq replaces the ISC dhcpd integration with a DHCP 
server integrated into dnsmasq. Versions 2.0-2.5 removed the ISC 
integration completely, but in version 2.6 it was re-enabled for 
backwards compatibility purposes. The change to an integrated DHCP 
server has the following advantages:

* Small. ISC dhcpd is a large and comprehensive DHCP solution. The
  dnsmasq DHCP server adds about 15k to DNS-only dnsmasq and provides
  all the facilities likely to be needed in the sort of networks
  which are targeted by dnsmasq.

* Easy to configure. All configuration is in one file and there are
  sensible defaults for common settings. Many applications will need
  just one extra line in /etc/dnsmasq.conf which tells it the range of
  addresses to allocate to DHCP.

* Support for static leases. When static leases are used with ISC DHCP
  they don't appear in the dhcp.leases file (since that file is used
  for storage of dynamic leases which aren't pre-configured.) Hence
  static leases cannot be used with dnsmasq unless each machine with a
  static lease is also inserted into /etc/hosts. This is not required
  with the dnsmasq DHCP server.


       DHCP configuration
       ------------------

To convert an installation which is currently using ISC dhcpd, remove
the ISC DHCP daemon. Unless you want dnsmasq to use the same file
to store its leases it is necessary to remove the configuration line in
/etc/dnsmasq.conf which specifies the dhcp.leases file.

To enable DHCP, simply add a line like this to /etc/dnsmasq.conf

dhcp-range=192.168.0.100,192.168.0.200,12h

which tells dnsmasq to us the addresses 192.168.0.100 to 192.168.0.200
for dynamic IP addresses, and to issue twelve hour leases.

Each host will have its default route and DNS server set to be the
address of the host running dnsmasq, and its netmask and broadcast 
address set correctly, so nothing else at all is required for a
minimal system. Hosts which include a hostname in their DHCP request 
will have that name and their allocated address inserted into the DNS,
in the same way as before.

Having started dnsmasq, tell any hosts on the network to renew their
DHCP lease, so that dnsmasq's  DHCP server becomes aware of them. For
Linux, this is best done by killing-and-restarting the DHCP client
daemon or taking the network interface down and then back up. For 
Windows 9x/Me, use the graphical tool "winipcfg". For Windows
NT/2000/XP, use the command-line "ipconfig /renew"

For more complex DHCP configuration, refer to the doc/setup.html, the
dnsmasq manpage and the annotated example configuration file. Also
note that for some ISC dhcpd to dnsmasq DHCP upgrades there may be
firewall issues: see the FAQ for details of this.


