All things related to multicast

["Marshall Eubanks" <>]

On Tue, 02 Sep 2003 21:43:55 -0500
 "David Farmer" 
<>
 wrote:
> What is your opinion of BOGON filters in general?  
> 
> In your opinion, is there anything particularly more problematic with 
> a Multicast BOGON filter compared to a Unicast BOGON filter?
> 
> I'd suggest adding a section about Reserved Groups in your Draft 
> on IPv4 Multicast Unusable Groups and Source Addresses.  Even 
> if you come down against filtering them I think some discussion 
> would be useful, espically since technically they shouldn't be used.
> 

I think what Bill is worried about, and I know what I would worry about,
is that one fine day these blocks would be assigned (say for a 
embedded RP scheme), and long forgotten filters would cripple
the new service and cause grief all around.

Upon thinking about it a little more, I am not too worried about it. The time
constant on introducing any new service would be long enough that fixing
people's filters would just be part of the noise.

Marshall


> On 2 Sep 2003 Bill Nickless wrote:
> 
> > My $0.02;
> > 
> > Please don't block multicast group addresses, unless you have an 
> > automated 
> > way to check the ARIN allocations and update your filters when ARIN 
> > does allocate space for use.
> > 
> > (I dropped my laptop and have had no end of grief fixing it, which is my 
> > poor excuse for not updating my two Internet Drafts before now.)
> > 
> > On Tue, 2 Sep 2003, David Farmer wrote:
> > 
> > > I had cause to take a look at RFC 3171 today.
> > > 
> > > So, I have a multicast best common practice (BCP) question.
> > > 
> > > Since 225.0.0.0 - 231.255.255.255 and 234.0.0.0 - 
> > > 238.255.255.255 are reserved per section 2 and per section 11 
> > > reserved space is not to be used by applications should any traffic 
> > > destine to these locations be consider BOGON until assigned?
> > > 
> > > Would it be a bad idea to block it?  Particularly at an administrative 
> > > boundary.
> > > 
> > > I don't see any discussion of reserved space in Bill Nickless' 
> > > Internet Draft related to these issues.
> > > 
> > > http://www.ietf.org/internet-drafts/draft-nickless-ipv4-mcast-
> > > unusable-02.txt
> > > 
> > > What do others think?  I what problems do you see in doing 
> > > something like this?  
> > > 
> > > For sure you would have to monitor any new IANA assignments 
> > > and update the filters to allow any new assignments.  But this 
> > > shouldn't be anymore work that any other BOGON filters.
> > > 
> > > =================================================
> > > David Farmer                              Email:  
> > > 
> > > Office of Information Technology
> > > University of Minnesota                   Phone:  612-626-0815
> > > 2218 University Ave SE                    Cell:   612-812-9952
> > > Minneapolis, MN 55414-3029                FAX:    612-624-4035
> > > =================================================
> > > 
> > > 
> > 
> > 
> 
> 
> =================================================
> David Farmer                          Email:  
> 
> Office of Information Technology
> University of Minnesota                       Phone:  612-626-0815
> 2218 University Ave SE                        Cell:   612-812-9952
> Minneapolis, MN 55414-3029            FAX:    612-624-4035
> =================================================
>