WHY THE HELL IS THERE A UTUN0 ON MY SYSTEM?

So, I was doing some hacking about today, and I noticed all of a sudden I had a shiny new utun0 interface on my Mac Mini. Needless to say, I was panicked.

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 utun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1380
 inet6 fe80::d89b:9a8a:xxxx:xxxx%utun0 prefixlen 64 scopeid 0xa
 inet6 fd1b:6be5:9aec:1374:d89b:xxxx:xxxx:xxxx prefixlen 64 

What the bloody bloody is this, I hear you ask?!

It turns out that BackToMyMac makes this happen using racoon

0 211 1 0 1:53pm ?? 0:00.07 /usr/sbin/racoon -D

Based on the configuration at /private/var/run/racoon and /private/etc/racoon

I turned it off, but only after noting that I liked that it’s one of the few in the wild implementations of anything using solely IPv6 I’ve seen….