1
2
3	Upgrading to dnsmasq V2
4        -----------------------
5
6Version 1.x of dnsmasq includes a facility for reading the dhcp.leases
7file written by ISC dhcpd. This allows the names of machines which
8have addresses allocated by DHCP to be included in the DNS.
9
10Version 2.x of dnsmasq replaces the ISC dhcpd integration with a DHCP 
11server integrated into dnsmasq. Versions 2.0-2.5 removed the ISC 
12integration completely, but in version 2.6 it was re-enabled for 
13backwards compatibility purposes. The change to an integrated DHCP 
14server has the following advantages:
15
16* Small. ISC dhcpd is a large and comprehensive DHCP solution. The
17  dnsmasq DHCP server adds about 15k to DNS-only dnsmasq and provides
18  all the facilities likely to be needed in the sort of networks
19  which are targeted by dnsmasq.
20
21* Easy to configure. All configuration is in one file and there are
22  sensible defaults for common settings. Many applications will need
23  just one extra line in /etc/dnsmasq.conf which tells it the range of
24  addresses to allocate to DHCP.
25
26* Support for static leases. When static leases are used with ISC DHCP
27  they don't appear in the dhcp.leases file (since that file is used
28  for storage of dynamic leases which aren't pre-configured.) Hence
29  static leases cannot be used with dnsmasq unless each machine with a
30  static lease is also inserted into /etc/hosts. This is not required
31  with the dnsmasq DHCP server.
32
33
34       DHCP configuration
35       ------------------
36
37To convert an installation which is currently using ISC dhcpd, remove
38the ISC DHCP daemon. Unless you want dnsmasq to use the same file
39to store its leases it is necessary to remove the configuration line in
40/etc/dnsmasq.conf which specifies the dhcp.leases file.
41
42To enable DHCP, simply add a line like this to /etc/dnsmasq.conf
43
44dhcp-range=192.168.0.100,192.168.0.200,12h
45
46which tells dnsmasq to us the addresses 192.168.0.100 to 192.168.0.200
47for dynamic IP addresses, and to issue twelve hour leases.
48
49Each host will have its default route and DNS server set to be the
50address of the host running dnsmasq, and its netmask and broadcast 
51address set correctly, so nothing else at all is required for a
52minimal system. Hosts which include a hostname in their DHCP request 
53will have that name and their allocated address inserted into the DNS,
54in the same way as before.
55
56Having started dnsmasq, tell any hosts on the network to renew their
57DHCP lease, so that dnsmasq's  DHCP server becomes aware of them. For
58Linux, this is best done by killing-and-restarting the DHCP client
59daemon or taking the network interface down and then back up. For 
60Windows 9x/Me, use the graphical tool "winipcfg". For Windows
61NT/2000/XP, use the command-line "ipconfig /renew"
62
63For more complex DHCP configuration, refer to the doc/setup.html, the
64dnsmasq manpage and the annotated example configuration file. Also
65note that for some ISC dhcpd to dnsmasq DHCP upgrades there may be
66firewall issues: see the FAQ for details of this.
67
68
69