1<HTML> 2<HEAD> 3<TITLE> Dnsmasq - a DNS forwarder for NAT firewalls.</TITLE> 4</HEAD> 5<BODY BGCOLOR="WHITE"> 6<H1 ALIGN=center>Dnsmasq</H1> 7Dnsmasq is a caching DNS forwarder designed to provide DNS service on a 8small network. It is targeted at home networks using NAT and 9connected to the internet via a modem, cable-modem or ADSL 10connection but would be a good choice for any small network where low 11resource use and ease of configuration are important. 12<P> 13Dnsmasq is included in at least the following Linux distributions: Gentoo, Debian, 14Smoothwall, IP-Cop, floppyfw, and Firebox. 15<P> 16Dnsmasq provides the following features: 17<DIR> 18 19<LI> 20The DNS configuration of machines behind the firewall is simple and 21doesn't depend on the details of the ISP's dns servers 22<LI> 23Clients which try to do DNS lookups while a modem link to the 24internet is down will time out immediately. 25</LI> 26<LI> 27Dnsmasq will serve names from the /etc/hosts file on the firewall 28machine: If the names of local machines are there, then they can all 29be addressed without having to maintain /etc/hosts on each machine. 30</LI> 31<LI> 32Dnsmasq will serve names from the DHCP leases file on the firewall machine: 33If machines specify a hostname when they take out a DHCP lease, then they are 34addressable in the local DNS. 35</LI> 36<LI> 37Dnsmasq caches internet addresses (A records and AAAA records) and address-to-name 38mappings (PTR records), reducing the load on upstream servers and 39improving performance (especially on modem connections). From version 400.95 the cache honours time-to-live information and removes old 41records as they expire. From version 0.996 dnsmasq does negative 42caching. From version 1.2 dnsmasq supports IPv6 addresses, both 43in its cache and in /etc/hosts. 44</LI> 45<LI> 46Dnsmasq can be configured to automatically pick up the addresses of 47it's upstream nameservers from ppp or dhcp configuration. It will 48automatically reload this information if it changes. This facility 49will be of particular interest to maintainers of Linux firewall 50distributions since it allows dns configuration to be made automatic. 51</LI> 52<LI> 53On IPv6-enabled boxes, dnsmasq can both talk to upstream servers via IPv6 54and offer DNS service via IPv6. On dual-stack (IPv4 and IPv6) boxes it talks 55both protocols and can even act as IPv6-to-IPv4 or IPv4-to-IPv6 forwarder. 56</LI> 57<LI> 58Dnsmasq can be configured to send queries for certain domains to 59upstream servers handling only those domains. This makes integration 60with private DNS systems easy. 61</LI> 62</DIR> 63<P> 64Dnsmasq has one further feature; it can be configured to return an MX record 65for the firewall host. This makes it easy to configure the mailer on the local 66machines to forward all mail to the central mailer on the firewall host. Never 67lose root messages from your machines again! 68 69<H2>Download.</H2> 70 71Download dnsmasq <A HREF="http://www.thekelleys.org.uk/dnsmasq/"> here</A>. 72The tarball includes this documentation, source, manpage and control files for building .rpms. 73There are also pre-built i386 .rpms, and a 74<A HREF="http://www.thekelleys.org.uk/dnsmasq/CHANGELOG"> CHANGELOG</A>. 75Dnsmasq is part of the Debian distribution, it can be downloaded from 76<A HREF="http://ftp.debian.org/debian/pool/main/d/dnsmasq/"> here</A> or installed using <TT>apt</TT>. 77 78 79<H2>Building rpms.</H2> 80Assuming you have the relevant tools installed, you can rebuild .rpms simply by running (as root) 81 82<PRE> 83rpm -ta dnsmasq-xxx.tar.gz 84</PRE> 85 86<H2>License.</H2> 87Dnsmasq is distributed under the GPL. See the file COPYING in the distribution 88for details. 89 90<H2>Contact.</H2> 91Dnsmasq was written by Simon Kelley. You can contact me at <A HREF="mailto:simon@thekelleys.org.uk">simon@thekelleys.org.uk</A>. Bugreports, patches, and suggestions for improvements gratefully accepted. 92</BODY> 93 94