Tunnel broker

Tunnel broker

A tunnel broker is a service which provides a network tunnel. These tunnels can provide encapsulated connectivity over existing infrastructure to a new infrastructure.

There are a variety of tunnel brokers, though most commonly the term is used to refer to an IPv6 tunnel broker, as defined in .These commonly provide IPv6 tunnels to endusers/endsites using either manual, scripted or automatic configuration. In general tunnel brokers offer so called 'protocol 41' or proto-41 tunnels. These are tunnels where IPv6 is tunneled directly inside IPv4 by having the protocol field set to '41' (IPv6) in the IPv4 packet.

Automatic configuration

Automatic configuration is usually done using the Tunnel Setup Protocol (TSP), or using Tunnel Information Control protocol (TIC).A single client capable of this is AICCU (Automatic IPv6 Connectivity Client Utility)

NAT Issues

proto-41 tunnels (direct IPv6 in IPv4) may not operate well with NATs. One way around this is to configure the actual endpoint of the tunnel to be the DMZ on the NAT-box. Another method is to either use AYIYA or Hexago's V6-UDP-V4 tunneling protocol (described in the TSP draft), both of which send IPv6 inside UDP, which is able to cross most NAT setups and even firewalls.

A problem that still might occur is that of the timing out of the state in the NAT machine. As a NAT remembers that a packet went outside to the Internet it allows another packet to come back in from the Internet that is related to the initial proto-41 packet. When this state expires, no other packets from the Internet will be accepted. This therefore breaks the connectivity of the tunnel until the user's host again sends out a packet to the Tunnel Broker.

Dynamic Endpoints

When the endpoint isn't a static IP address, the user, or a program, has to instruct the tunnel broker to update the endpoint address. This can be done using the tunnel broker's Website or using an automated protocol like [http://www.sixxs.net/tools/heartbeat/ Heartbeat] as used by AICCU. In the case of a tunnel broker using TSP, restarting the tunnel will have a similar effect as then the tunnel broker is also instructed to update the IP address on the user's side of the tunnel.

See also

*List of IPv6 tunnel brokers

External links

* [http://www.sixxs.net/tools/aiccu/brokers/ Tunnel Brokers] page

Wikimedia Foundation. 2010.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • tunnel broker — noun (computer networking) a service which provides a network tunnel …   Wiktionary

  • Broker (disambiguation) — A broker is a party that mediates between a buyer and a seller.Broker may also refer to:* Broker, Outer Hebrides, a small hamlet next to the village of Portvoller and Portnaguran * The Power Broker , 1974 biography of Robert Moses * The Broker ,… …   Wikipedia

  • Tunnel Setup Protocol — Le Tunnel Setup Protocol est un protocole réseau utilisé pour négocier les paramètres d un tunnel entre une machine cliente et le système d un fournisseur de tunnel. Ce protocole est défini par la RFC 5572[1]. TSP est essentiellement utilisé dans …   Wikipédia en Français

  • Tunnel Setup Protocol — In computer networking, Tunnel Setup Protocol (TSP) is a signalling protocol used to negotiate tunnel setup parameters between two tunnel end points. TSP is implemented in a client server architecture. Current Revision The current revision of the …   Wikipedia

  • List of IPv6 tunnel brokers — The following is a list of IPv6 tunnel brokers [ [http://www.sixxs.net/tools/aiccu/brokers/ AICCU Tunnelbroker Support, lists Tunnel Brokers that are supported and unsupported by AICCU] ] that conform to the principles of RFC 3053 which describes …   Wikipedia

  • IP tunnel — IP tunnelling is a method to connect two disjoint Internet Protocol (IP) networks, that don t have a native routing path, to each other via a communications channel (the IP tunnel) that uses encapsulation technologies across an intermediate… …   Wikipedia

  • Brooklyn-Battery Tunnel — Das Tunnelportal in Brooklyn Nutzung Straßentunnel Verkehrsverbindung Interstate 478 …   Deutsch Wikipedia

  • AICCU — Infobox Software name = AICCU caption = Automatic IPv6 Connectivity Client Utility developer = released = [http://www.sixxs.net/tools/aiccu/history/ 1 August 2004 (beta1)] frequently updated = yes programming language = C (programming language)… …   Wikipedia

  • IPv6 — Internet protocol suite Application layer BGP DHCP DNS FTP …   Wikipedia

  • Ipv6 — Pile de protocoles 7 • Application 6 • Présentation 5 • Session 4 • Transport …   Wikipédia en Français

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”