I was asked to file a PR regarding the existing documentation on setting up IPv6 with a tunnel. re https://www.freebsd.org/doc/handbook/network-ipv6.html Specifcally: gifconfig is deprecated. Use cloned_interfaces="gif0" instead.
A commit references this bug: Author: wblock Date: Fri Sep 2 18:11:32 UTC 2016 New revision: 49364 URL: https://svnweb.freebsd.org/changeset/doc/49364 Log: IPv6 handbook should refer to cloned_interfaces, not gifconfig. Bug report by dvl@, patch supplied by Tim Moore <timmoore88_gmail.com>. PR: 193523 Submitted by: dvl@FreeBSD.org Differential Revision: https://reviews.freebsd.org/D7760 Changes: head/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.xml
Committed, thanks!