Skip to Content.
Sympa Menu

wg-multicast - Re: constraining that pesky 239.255/16 traffic in a CGMP Borg

Subject: All things related to multicast

List archive

Re: constraining that pesky 239.255/16 traffic in a CGMP Borg


Chronological Thread 
  • From: Ronan Kelly <>
  • To: Mark Quigley <>
  • Cc: Amel Caldwell <>, Alan Crosswell <>, wg-multicast <>
  • Subject: Re: constraining that pesky 239.255/16 traffic in a CGMP Borg
  • Date: Fri, 03 Oct 2003 09:04:35 +0100

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

Attachment: smime.p7s
Description: S/MIME Cryptographic Signature




Archive powered by MHonArc 2.6.16.

Top of Page