Do 6in4/SIT Tunnels run on a specific port?

[helpdeskaleer]

Hello,

I am trying to setup a 6in4 Tunnel on an OpenWRT Router.

I thought that I could put my router on the Xfinity DMZ to get it working, but I was told that it wouldn't work because my Xfinity Router needed to be put in Bridge Mode for it to work.

I scoured various sources for information on Linux SIT Tunnels and what port they use, but I haven't been able to find anything on it.

Is this because it runs on a OSI Layer that doesn't include ports, and makes it require bridge mode?

[kcochran]

6in4 is simply a IPv6 packet with an IPv4 header stuck on top of it, and the protocol field set to 41.  No TCP, UDP or other header in the middle, so no port information to latch onto.