All things related to multicast

[Ronan Kelly <>]

Hi all,

We are using the config below.
I just want to confirm something, we are blocking 239/8.
You guys were mentioning 239.255/16.
I thought 239/8 was the private address range, hence why we block that 
on the edge of our AS.
Is this correct?

Ronan


interface POS3/0
description
bandwidth 2500000
ip address 62.40.103.230 255.255.255.252
no ip unreachables
no ip directed-broadcast
ip pim bsr-border
ip pim sparse-mode
ip multicast boundary 24
no ip mroute-cache
ipv6 address 2001:798:2019:10AA::2/126
--More--
Standard IP access list 24
   deny   224.0.1.39
   deny   224.0.1.40 (5 matches)
   deny   239.0.0.0, wildcard bits 0.255.255.255
   permit 224.0.0.0, wildcard bits 15.255.255.255

Mark Quigley wrote:

> We have "ip multicast boundary" configured on our pnwgp link. The docs
> state:
>
> Use this command to configure an administratively scoped boundary on an
> interface to filter multicast group addresses in the range defined by the
> access-list argument. A standard access list defines the range of addresses
> affected. When this command is configured, no multicast data packets are
> allowed to flow across the boundary from either direction. Restricting
> multicast data packet flow enables reuse of the same multicast group address
> in different administrative domains.
>
> Our filter looks like:
> ip access-list standard multicast-boundary
> deny   224.0.1.39
> deny   224.0.1.40
> deny   239.0.0.0 0.255.255.255
> permit any
>
> Good luck
> -
> Mark Quigley                                   (208) 885 6721 ph
> Information Technology Services    (208) 885 7539 fax
> University of Idaho                          
>
> Moscow ID 83844-3155                  http://www.uidaho.edu/~markq
> ----- Original Message ----- 
> From: "Amel Caldwell" <>
> To: "Alan Crosswell" 
> <>
> Cc: "wg-multicast" 
> <>
> Sent: Thursday, October 02, 2003 2:45 PM
> Subject: Re: constraining that pesky 239.255/16 traffic in a CGMP Borg
>
>
>  
>
> > Alan--
> >
> > I modified our inbound spoofing filters to deny ip any 239.255.0.0
> >    
> 0.0.255.255
>  
>
> > before permitting the local subnet traffic out.  I don't know the
> > ramifications on CGMP on this approach though.
> >
> > Amel
> >
> > On Thu, 2 Oct 2003, Alan Crosswell wrote:
> >
> >    
> >
> > > I want to define site-local as the same as link-local to constrain all
> > > the hokey SSDP and other 239.255/16 traffic on my campus.  Can anyone
> > > suggest the "right" way to do this?  I've tried blocking registers to
> > > the RP with "ip pim accept-register" which results in a syslog for each
> > > register attempt that is ignored, causing a lot of clutter.
> > >
> > > I've also tried "ip igmp access-group" on the individual router
> > > interfaces since I really don't want to know about these groups.
> > > However, this has wierd CGMP ramifications it seems:  membership reports
> > > seem to cause the switch to get a CGMP join for the GDA.  v2 leaves
> > > however do not cause a CGMP leave to make it to the switch, so the
> > > static cam entry hangs aroud forever.
> > >
> > > /a
> > >
> > >
> > >      
> >    
>
>
>  


--
Ronan Kelly,   (CCNP, JNCIA) 
HEAnet Ltd, 
Brooklawn House, 
Shelbourne Rd, 
Dublin 4. 
Email:, 
Phone +353 (0)1 6609040, 
FAX +353 (0)1 6603666

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