What protocol is Window's v6v4tunnel implementing?

Question

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

>netsh interface ipv6 add v6v4tunnel "My Tunnel" 192.168.1.13 209.51.181.2

My question is: what protocol is this?

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

• 6to4: RFC3056 - Connection of IPv6 Domains via IPv4 Clouds
• isatap: RFC5214 - Intra-Site Automatic Tunnel Addressing Protocol (ISATAP)
• teredo: RFC4380 - Teredo: Tunneling IPv6 over UDP through Network Address Translations (NATs)
• v6v4tunnel: ?
• httpstunnel: ?
• portproxy: ?

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

• Technet: IPv6 Transition Technologies (TechRef)

Answer 1

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.

Answer 2

IPv6 transition technologies in Microsoft Windows:

• Tunneling
  • v6v4tunnel: Configured Tunneling, 6in4, SIT, RFC 4213
  • 6to4: RFC 3056
  • teredo: RFC 4380
  • isatap: RFC 5214
  • httpstunnel: IP over HTTPS (IP-HTTPS) Tunneling, MS-IPHTTPS
• Relay or Proxy
  • portproxy: TCP Proxy