docs/182218: Add an ipfilter rc.conf option in handbook for IPv6

[ShelLuser]

>Number:         182218
>Category:       docs
>Synopsis:       Add an ipfilter rc.conf option in handbook for IPv6
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-doc
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Thu Sep 19 01:50:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator:     ShelLuser
>Release:        9.1-RELEASE-P7
>Organization:
>Environment:
FreeBSD smtp2.losoco.com 9.1-RELEASE-p7 FreeBSD 9.1-RELEASE-p7 #3 r255465: Wed Sep 11 03:35:14 CEST 2013     root at smtp2.losoco.com:/usr/obj/usr/src/sys/SMTP2  amd64

>Description:
I'm one of the lucky people to have found a hosting provider which supports both IPv4 /and/ IPv6 (native /64 IPv6 netblock on each server).

My firewall of choice: IPFilter, mainly because of my Sun Solaris / SunOS roots.
Why I don't switch: "If it isn't broken...".

I'm reading:
http://www.freebsd.org/doc/handbook/firewalls-ipf.html

Section 30.5.3 lists the options one can use in rc.conf but only those for IPv4, people using IPv6 are left in the dark.

>How-To-Repeat:

>Fix:
(note that these are only suggestions)

Add the following line:

ipv6_ipfilter_rules="/etc/ipf6.rules" # loads rules definition text file for IPv6

..after this existing line:

ipfilter_rules="/etc/ipf.rules" # loads rules definition text file


>Release-Note:
>Audit-Trail:
>Unformatted: