Tunnelbrokernet

Tunnelbroker.net is a free service that provides IPv6 tunnel brokering to users and organizations. Established in 2001, it is one of the oldest and most well-known tunnel brokers. The service allows individuals and entities to obtain an IPv6 network prefix that can be routed over an existing IPv4 network infrastructure. This is particularly useful for those who do not yet have native IPv6 connectivity from their Internet Service Provider.

The primary mechanism used by tunnelbroker.net is the 6in4 tunnel, also known as an IPv6-in-IPv4 tunnel. In this setup, IPv6 packets are encapsulated within IPv4 packets, allowing them to traverse the IPv4 internet. When an IPv6 packet reaches the tunnel endpoint on the server side, the IPv4 header is stripped, and the original IPv6 packet is forwarded to its destination on the IPv6 internet. Conversely, incoming IPv6 traffic destined for the tunnel is encapsulated in IPv4 and sent to the client's tunnel endpoint.

Users typically need to register an account on the tunnelbroker.net website to obtain a tunnel. This process usually involves providing an external IPv4 address, which is required for the tunnel endpoint. Once the tunnel is created, the user configures their local router or host to establish the tunnel connection. The service provides tools and documentation to assist with this configuration, supporting various operating systems and network devices. Tunnelbroker.net plays a significant role in promoting IPv6 adoption by making it accessible to a wider audience before widespread native IPv6 deployment is complete.