doc.html - thekelleys/dnsmasq - Gitiles

 <HTML>
 <HEAD>
 <TITLE> Dnsmasq - a DNS forwarder for NAT firewalls.</TITLE>
 </HEAD>
 <BODY BGCOLOR="WHITE">
 <H1 ALIGN=center>Dnsmasq</H1>
 Dnsmasq is lightweight, easy to configure DNS forwarder and DHCP
  server. It is designed to provide DNS and, optionally, DHCP, to a
  small network. It can serve the names of local machines which are
  not in the global DNS. The DHCP server integrates with the DNS
  server and allows machines with DHCP-allocated addresses
  to appear in the DNS with names configured either in each host or
  in a central configuration file. Dnsmasq supports static and dynamic
  DHCP leases and BOOTP for network booting of diskless machines.
 <P>
  Dnsmasq is targeted at home networks using NAT and
 connected to the internet via a modem, cable-modem or ADSL
 connection but would be a good choice for any small network where low
 resource use and ease of configuration are important.
 <P>
 Dnsmasq is included in at least the following Linux distributions: Gentoo, Debian,
 Smoothwall, IP-Cop, floppyfw, Firebox, Freesco and
 Clarkconnect. It is also available as a FreeBSD port and is used in Linksys wireless routers.
 <P>
 Dnsmasq provides the following features:
 <DIR>

 <LI>
 The DNS configuration of machines behind the firewall is simple and
 doesn't depend on the details of the ISP's dns servers
 <LI>
 Clients which try to do DNS lookups while  a modem link to the
 internet is down will time out immediately.
 </LI>
 <LI>
 Dnsmasq will serve names from the /etc/hosts file on the firewall
 machine: If the names of local machines are there, then they can all
 be addressed without having to maintain /etc/hosts on each machine.
 </LI>
 <LI>
 Dnsmasq will serve names from the DHCP leases file on the firewall machine:
 If machines specify a hostname when they take out a DHCP lease, then they are
 addressable in the local DNS. <B>UPDATE</B> Dnsmasq version 2 now offers an integrated DHCP server
 instead of the lease file reader. This gives better control of the
 interaction with new functions (for example fixed IP leasess and
 attaching names to ethernet addresses centrally) it's also much
 smaller than dnsmasq and ISC dhcpd which is important for router distros.
 </LI>
 <LI>
 Dnsmasq caches internet addresses (A records and AAAA records) and address-to-name
 mappings (PTR records), reducing the load on upstream servers and
 improving performance (especially on modem connections). From version
 0.95 the cache honours time-to-live information and removes old
 records as they expire. From version 0.996 dnsmasq does negative
 caching. From version 1.2 dnsmasq supports IPv6 addresses, both
 in its cache and in /etc/hosts.
 </LI>
 <LI>
 Dnsmasq can be configured to automatically pick up the addresses of
 it's upstream nameservers from ppp or dhcp configuration. It will
 automatically reload this information if it changes. This facility
 will be of particular interest to maintainers of Linux firewall
 distributions since it allows dns configuration to be made automatic.
 </LI>
 <LI>
 On IPv6-enabled boxes, dnsmasq can both talk to upstream servers via IPv6
 and offer DNS service via IPv6. On dual-stack (IPv4 and IPv6) boxes it talks
 both protocols and can even act as IPv6-to-IPv4 or IPv4-to-IPv6 forwarder.
 </LI>
 <LI>
 Dnsmasq can be configured to send queries for certain domains to
 upstream servers handling only those domains. This makes integration
 with private DNS systems easy.
 </LI>
 <LI>
 Dnsmasq can be configured to return an MX record
 for the firewall host. This makes it easy to configure the mailer on the local
 machines to forward all mail to the central mailer on the firewall host. Never
 lose root messages from your machines again!
 </LI>
 <LI>
 For version 1.15 dnsmasq has a facility to work around Verisign's infamous wildcard A record
 in the .com and .net TLDs
 </LI>
 </DIR>

 <H2>Download.</H2>

 Download dnsmasq <A HREF="http://www.thekelleys.org.uk/dnsmasq/"> here</A>.
 The tarball includes this documentation, source, manpage and control files for building .rpms.
 There are also pre-built i386 .rpms, and a
 <A HREF="CHANGELOG"> CHANGELOG</A>.
 Dnsmasq is part of the Debian distribution, it can be downloaded from
 <A HREF="http://ftp.debian.org/debian/pool/main/d/dnsmasq/"> here</A> or installed using <TT>apt</TT>.


 <H2>Building rpms.</H2>
 Assuming you have the relevant tools installed, you can rebuild .rpms simply by running (as root)

 <PRE>
 rpmbuild -ta dnsmasq-xxx.tar.gz
 </PRE>

 Note for Suse users: you will need to re-compress the tar file as
 bzip2 before building using the commands
 <PRE>
 gunzip dnsmasq-xxx.tar.gz
 bzip2 dnsmasq-zzz.tar
 </PRE>

 <H2>Links.</H2>
 Ulrich Ivens has a nice HOWTO in German on installing dnsmasq at <A HREF="http://howto.linux-hardware-shop.de/dnsmasq.html">http://howto.linux-hardware-shop.de/dnsmasq.html</A>

 <H2>License.</H2>
 Dnsmasq is distributed under the GPL. See the file COPYING in the distribution
 for details.

 <H2>Contact.</H2>
 Dnsmasq 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.
 </BODY>
	<HTML>
	<HEAD>
	<TITLE> Dnsmasq - a DNS forwarder for NAT firewalls.</TITLE>
	</HEAD>
	<BODY BGCOLOR="WHITE">
	<H1 ALIGN=center>Dnsmasq</H1>
	Dnsmasq is lightweight, easy to configure DNS forwarder and DHCP
	server. It is designed to provide DNS and, optionally, DHCP, to a
	small network. It can serve the names of local machines which are
	not in the global DNS. The DHCP server integrates with the DNS
	server and allows machines with DHCP-allocated addresses
	to appear in the DNS with names configured either in each host or
	in a central configuration file. Dnsmasq supports static and dynamic
	DHCP leases and BOOTP for network booting of diskless machines.
	<P>
	Dnsmasq is targeted at home networks using NAT and
	connected to the internet via a modem, cable-modem or ADSL
	connection but would be a good choice for any small network where low
	resource use and ease of configuration are important.
	<P>
	Dnsmasq is included in at least the following Linux distributions: Gentoo, Debian,
	Smoothwall, IP-Cop, floppyfw, Firebox, Freesco and
	Clarkconnect. It is also available as a FreeBSD port and is used in Linksys wireless routers.
	<P>
	Dnsmasq provides the following features:
	<DIR>

	<LI>
	The DNS configuration of machines behind the firewall is simple and
	doesn't depend on the details of the ISP's dns servers
	<LI>
	Clients which try to do DNS lookups while a modem link to the
	internet is down will time out immediately.
	</LI>
	<LI>
	Dnsmasq will serve names from the /etc/hosts file on the firewall
	machine: If the names of local machines are there, then they can all
	be addressed without having to maintain /etc/hosts on each machine.
	</LI>
	<LI>
	Dnsmasq will serve names from the DHCP leases file on the firewall machine:
	If machines specify a hostname when they take out a DHCP lease, then they are
	addressable in the local DNS. <B>UPDATE</B> Dnsmasq version 2 now offers an integrated DHCP server
	instead of the lease file reader. This gives better control of the
	interaction with new functions (for example fixed IP leasess and
	attaching names to ethernet addresses centrally) it's also much
	smaller than dnsmasq and ISC dhcpd which is important for router distros.
	</LI>
	<LI>
	Dnsmasq caches internet addresses (A records and AAAA records) and address-to-name
	mappings (PTR records), reducing the load on upstream servers and
	improving performance (especially on modem connections). From version
	0.95 the cache honours time-to-live information and removes old
	records as they expire. From version 0.996 dnsmasq does negative
	caching. From version 1.2 dnsmasq supports IPv6 addresses, both
	in its cache and in /etc/hosts.
	</LI>
	<LI>
	Dnsmasq can be configured to automatically pick up the addresses of
	it's upstream nameservers from ppp or dhcp configuration. It will
	automatically reload this information if it changes. This facility
	will be of particular interest to maintainers of Linux firewall
	distributions since it allows dns configuration to be made automatic.
	</LI>
	<LI>
	On IPv6-enabled boxes, dnsmasq can both talk to upstream servers via IPv6
	and offer DNS service via IPv6. On dual-stack (IPv4 and IPv6) boxes it talks
	both protocols and can even act as IPv6-to-IPv4 or IPv4-to-IPv6 forwarder.
	</LI>
	<LI>
	Dnsmasq can be configured to send queries for certain domains to
	upstream servers handling only those domains. This makes integration
	with private DNS systems easy.
	</LI>
	<LI>
	Dnsmasq can be configured to return an MX record
	for the firewall host. This makes it easy to configure the mailer on the local
	machines to forward all mail to the central mailer on the firewall host. Never
	lose root messages from your machines again!
	</LI>
	<LI>
	For version 1.15 dnsmasq has a facility to work around Verisign's infamous wildcard A record
	in the .com and .net TLDs
	</LI>
	</DIR>

	<H2>Download.</H2>

	Download dnsmasq <A HREF="http://www.thekelleys.org.uk/dnsmasq/"> here</A>.
	The tarball includes this documentation, source, manpage and control files for building .rpms.
	There are also pre-built i386 .rpms, and a
	<A HREF="CHANGELOG"> CHANGELOG</A>.
	Dnsmasq is part of the Debian distribution, it can be downloaded from
	<A HREF="http://ftp.debian.org/debian/pool/main/d/dnsmasq/"> here</A> or installed using <TT>apt</TT>.


	<H2>Building rpms.</H2>
	Assuming you have the relevant tools installed, you can rebuild .rpms simply by running (as root)

	<PRE>
	rpmbuild -ta dnsmasq-xxx.tar.gz
	</PRE>

	Note for Suse users: you will need to re-compress the tar file as
	bzip2 before building using the commands
	<PRE>
	gunzip dnsmasq-xxx.tar.gz
	bzip2 dnsmasq-zzz.tar
	</PRE>

	<H2>Links.</H2>
	Ulrich Ivens has a nice HOWTO in German on installing dnsmasq at <A HREF="http://howto.linux-hardware-shop.de/dnsmasq.html">http://howto.linux-hardware-shop.de/dnsmasq.html</A>

	<H2>License.</H2>
	Dnsmasq is distributed under the GPL. See the file COPYING in the distribution
	for details.

	<H2>Contact.</H2>
	Dnsmasq 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.
	</BODY>