--- embedaddon/dnsmasq/doc.html 2013/07/29 19:37:40 1.1.1.1 +++ embedaddon/dnsmasq/doc.html 2014/06/15 16:31:38 1.1.1.2 @@ -1,6 +1,6 @@ - Dnsmasq - a DNS forwarder for NAT firewalls. + Dnsmasq - network services for small networks. @@ -11,83 +11,49 @@

Dnsmasq

+Dnsmasq provides network infrastructure for small networks: DNS, DHCP, router advertisement and network boot. It is designed to be +lightweight and have a small footprint, suitable for resource constrained routers and firewalls. It has also been widely used +for tethering on smartphones and portable hotspots, and to support virtual networking in virtualisation frameworks. +Supported platforms include Linux (with glibc and uclibc), Android, *BSD, and Mac OS X. Dnsmasq is included in most +Linux distributions and the ports systems of FreeBSD, OpenBSD and NetBSD. Dnsmasq provides full IPv6 support. -Dnsmasq is a 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/TFTP/PXE for network booting of diskless machines.

- 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 smallish network (up to -1000 clients is known to work) where low -resource use and ease of configuration are important. +The DNS subsystem provides a local DNS server for the network, with forwarding of all query types to upstream recursive DNS servers and +cacheing of common record types (A, AAAA, CNAME and PTR, also DNSKEY and DS when DNSSEC is enabled). +

+
  • Local DNS names can be defined by reading /etc/hosts, by importing names from the DHCP subsystem, or by configuration of a wide range of useful record types.
  • +
  • Upstream servers can be configured in a variety of convenient ways, including dynamic configuration as these change on moving upstream network. +
  • Authoritative DNS mode allows local DNS names may be exported to zone in the global DNS. Dnsmasq acts as authoritative server for this zone, and also provides +zone transfer to secondaries for the zone, if required.
  • +
  • DNSSEC validation may be performed on DNS replies from upstream nameservers, providing security against spoofing and cache poisoning.
  • +
  • Specified sub-domains can be directed to their own upstream DNS servers, making VPN configuration easy.
  • +
  • Internationalised domain names are supported. +
  • -Supported platforms include Linux (with glibc and uclibc), Android, *BSD, -Solaris and Mac OS X. -Dnsmasq is included in at least the following Linux distributions: -Gentoo, Debian, Slackware, Suse, Fedora, -Smoothwall, IP-Cop, floppyfw, Firebox, LEAF, Freesco, fli4l, -CoyoteLinux, Endian Firewall and -Clarkconnect. It is also available as FreeBSD, OpenBSD and NetBSD ports and is used in -Linksys wireless routers (dd-wrt, openwrt and the stock firmware) and the m0n0wall project. -

    -Dnsmasq provides the following features: +The DHCP subsystem supports DHCPv4, DHCPv6, BOOTP and PXE.

    - -
  • -The DNS configuration of machines behind the firewall is simple and -doesn't depend on the details of the ISP's dns servers -
  • -Clients which try to do DNS lookups while a modem link to the -internet is down will time out immediately. -
  • -
  • -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. -
  • -
  • -The integrated DHCP server supports static and dynamic DHCP leases and -multiple networks and IP ranges. It works across BOOTP relays and -supports DHCP options including RFC3397 DNS search lists. -Machines which are configured by DHCP have their names automatically +
  • Both static and dynamic DHCP leases are supported, along with stateless mode in DHCPv6.
  • +
  • The PXE system is a full PXE server, supporting netboot menus and multiple architecture support. It +includes proxy-mode, where the PXE system co-operates with another DHCP server.
  • +
  • There is a built in read-only TFTP server to support netboot.
  • +
  • Machines which are configured by DHCP have their names automatically included in the DNS and the names can specified by each machine or -centrally by associating a name with a MAC address in the dnsmasq -config file. -
  • -
  • -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). -
  • -
  • -Dnsmasq can be configured to automatically pick up the addresses of -its 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. -
  • -
  • -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. -
  • -
  • -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. -
  • -
  • -Dnsmasq supports MX and SRV records and can be configured to return MX records -for any or all local machines. -
  • +centrally by associating a name with a MAC address or UID in the dnsmasq +configuration file.
    +

    +The Router Advertisement subsystem provides basic autoconfiguration for IPv6 hosts. It can be used stand-alone or in conjunction with DHCPv6. +

    +
  • The M and O bits are configurable, to control hosts' use of DHCPv6.
  • +
  • Router advertisements can include the RDNSS option.
  • +
  • There is a mode which uses name information from DHCPv4 configuration to provide DNS entries + for autoconfigured IPv6 addresses which would otherwise be anonymous.
  • +
    +

    + +For extra compactness, unused features may be omitted at compile time. +

    Get code.

    Download dnsmasq here. @@ -102,7 +68,7 @@ the repo, or get a copy using git protocol with the co
    git clone git://thekelleys.org.uk/dnsmasq.git 

    License.

    -Dnsmasq is distributed under the GPL. See the file COPYING in the distribution +Dnsmasq is distributed under the GPL, version 2 or version 3 at your discretion. See the files COPYING and COPYING-v3 in the distribution for details.

    Contact.

    @@ -110,7 +76,21 @@ There is a dnsmasq mailing list at http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss which should be the first location for queries, bugreports, suggestions etc. -Dnsmasq was written by Simon Kelley. You can contact me at simon@thekelleys.org.uk. + +

    Donations.

    +Dnsmasq is mainly written and maintained by Simon Kelley. For most of its life, dnsmasq has been a spare-time project. +These days I'm working on it as my main activity. +I don't have an employer or anyone who pays me regularly to work on dnsmasq. If you'd like to make +a contribution towards my expenses, please use the donation button below. +
    + + + + +
    + +