misc/74683: pf drops MLD reports

[Bernhard Schmidt]

>Number:         74683
>Category:       misc
>Synopsis:       pf drops MLD reports
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Dec 04 18:20:15 GMT 2004
>Closed-Date:
>Last-Modified:
>Originator:     Bernhard Schmidt
>Release:        5.3-STABLE
>Organization:
none
>Environment:
FreeBSD heimdall.birkenwald.de 5.3-STABLE FreeBSD 5.3-STABLE #0: Wed Nov 24 00:48:49 CET 2004     root at heimdall.birkenwald.de:/usr/obj/usr/src/sys/HEIMDALL  i386

>Description:
When pf firewall is enabled even with a most simple ruleset

pass all

an IPv6 multicast daemon like pim6sd or xorp on the machine cannot receive MLD reports from multicast clients trying to subscribe a group.

A pcap dump (ethereal or tcpdump) of a report sample is available for download at 

http://www.birkenwald.de/~berni/tmp/mld.dump

when pf is disabled with "pfctl -d" Multicast works fine
>How-To-Repeat:
- Compile a kernel with PF, PIM and MROUTING
- Install /usr/ports/net/pim6sd and configure
- Load simple pf ruleset "pass all"
- Startup pim6sd in debugging mode and subscribe from a client to an IPv6 multicast group
- pfctl -d
- subscribe again, now pim6sd can see the MLD reports
>Fix:
      
>Release-Note:
>Audit-Trail:
>Unformatted: