Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Microsoft Windows allows the creation of an "IPv6-in-IPv4 point-to-point tunnel":

>netsh interface ipv6 add v6v4tunnel "My Tunnel"

My question is: what protocol is this?

i know netsh exposes access to other tunneling or IPv6 transition protocols:

What protocol is v6v4tunnel implementing?

The reason i ask is because there's no documentation from Microsoft; so reading an RFC will have to be my documentation.

See also

share|improve this question
up vote 3 down vote accepted

v6v4tunnel is a simple 6in4 tunnel, using IPv6 in IPv4 proto-41 packets as defined in RFC 4213 ("host-to-router"). Sometimes this is called a "Protocol 41" tunnel.

This tunnel type is used by Tunnelbroker and other IPv6 tunnel providers. The Linux equivalent is a sit tunnel interface.

portproxy is a transport-layer proxy that listens for TCP connections and relays them to the configured destinations, similar to how 6tunnel works on Linux.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.