l2tp wins unused code
vpn_l2tp_configure in /etc/inc/vpn.inc
can use $l2tpcfg['wins'] for NetBIOS name server (NBNS) information
but that "wins" is not configured anywhere.
If it is not desired, then remove that stale code?
(I did see similar for vpn_pptp.php but this bug is about l2tp.)
(I noticed this while working on my book.
My list of bugs is at http://reedmedia.net/books/pfsense/bugs.html )