Subject: SDR: Addr/Port. ??

From: "Jean-Luc Parouty" <[email-masked]>
Date: Fri, 22 May 1998 17:34:47 +0200

Hello,

I try to find informations about address and port number used
by SDP / sdr...

I didn't found any informations in RFCs - This address is specified 
as "a well know address..." ;-)

The only information I found is:
ftp://ftp.isi.edu/in-notes/iana/assignments/multicast-addresses
but, there is no port number specified...

Of course, I could sniff my workstation, but it could be nice
to have a "paper reference"...

Thanks for advance - pjluc

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From: [email-masked] (Jeremy Hall)
Date: Fri, 22 May 1998 13:36:58 -0400 (EDT)

It uses 239.255.255.255 and 224.2.127.254 port 9875.

_J

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From: Mark Handley <[email-masked]>
Date: Fri, 22 May 1998 14:13:05 -0400

>I try to find informations about address and port number used

Global groups:  224.2.127.254/9875
Local scope groups: 239.255.255.255/9875
Other scopes: as configured.  

In general, the highest address in all admin scope zones should be
used, but there is no formal definition of the port, although 9875
would seem appropriate.

Cheers,
	Mark

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From: Henning Schulzrinne <[email-masked]>
Date: Fri, 22 May 1998 15:57:27 -0400

This information is collected at
http://www.cs.columbia.edu/~hgs/internet
-- 
Henning Schulzrinne   [email-masked]
Dept. of Comp. Sci.   ph  +1 212 939-7042
Columbia University   fax +1 212 666-0140
New York, NY 10027    http://www.cs.columbia.edu/~hgs

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From: Istvan Tetenyi <[email-masked]>
Date: Sat, 23 May 1998 07:22:13 +0200 (MET DST)

Hi,

Sorry, if it is an rtfm question.

We are about to introduce MBONE and multicasting in an environment
where: 

   Cisco 7000 --- ATM switch --- Catalyst 5000  
                (Lan emulation)    ethernet
                                    switch    

The DVMRP tunnel ends at the Cisco 7000. My question is: How
could one limit the multicast traffic only on those segments/ports on
the Catalyst that really participates in multicast sessions ? What
I would like to avoid is flooding those segments that do not listen
any multicast program.

In short are the ethernet switches IP multicast aware ?

I am aware that the switches work on level 2 and IP multicasting 
is at level 3.  Still the question might be valid. 

Any comment, suggestion is appreciated.

Kind regards,
Istvan

===========================================================================
Istvan Tetenyi					e-mail:[email-masked]
Computer and Automation Institute		phone: +361-149-7532
H-1132. Budapest, Victor Hugo u 18-22		fax: +361-129-7866
Hungary
===========================================================================

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From: Joe Loiacono <[email-masked]>
Date: Tue, 26 May 1998 08:20:38 -0400

Cisco has indicated that Cat 5000 Supervisor Engine Software, Release 2.3
and above makes use of "CGMP" to prevent broadcasting the packets to all
ports. On the switch:

1. Enable CGMP:  "set cgmp enable"
2. Indicate which port(s) have multicast routers attached: "set multicast
router mod_num/port_num"
3. Verify CGMP configuration:  "show multicast router", "show multicast
group", show cgmp stats [vlan_id]

When I first saw the flooding, I was concerned that it would interfere with
nominal traffic. A Cisco engineer had me measure the packet load on a
non-involved switch port. It was only 3% while an mbone session ran on
another port, which I guess isn't so bad.

Joe

>Any comment, suggestion is appreciated.
Joe Loiacono                             Phone: (301) 794-2509
Computer Sciences Corporation            Fax:   (301) 794-9530

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From: Toerless Eckert <[email-masked]>
Date: Tue, 26 May 1998 14:54:52 +0200 (MET DST)

One word of precaution on the use of CGMP:

CGMP is well suited to the typically low-bandwidth (i.e.: <= 2 Mbps
in sum) mbone multicast traffic, but if you want to run higher speed
company multicast, be sure that your router is attached via more than
10 Mbps:

   => With CGMP, all traffic within a VLAN will still still be seen by
      the multicast router for that VLAN.

I've seen some installations that do have big catalyst-5000 for the local
network and a 10-Mbps-ether/2-Mbps internet link via some router like a
cisco-25x0. With only a 10-Mbps links, the router can easily be overloaded
with high speed multicast traffic intended to be kept within the VLAN and thus
disturbing the wan connection. And if you go for 100-Mbps router,
be sure not to share the 100-Mbps ethernet with too many VLANs via ISL...

So as not to be misunderstood: This is not a drawback of CGMP that could
be overcome with a better protocol in the same environment - CGMP is probably
at the limit of what can be achieved whilst trying not to change all host
software. The problem is with IGMP on the hosts within the VLAN. Something
like GARP might help, but i don't see it coming..

Best regards
	Toerless

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From: "Christopher J. Tengi" <[email-masked]>
Date: Tue, 26 May 1998 10:19:32 -0400

> is at level 3.  Still the question might be valid. 

The catalyst 5000 is not aware of IP multicast participants by itself, but can 
learn about where to forward the multicast frames if you enable CGMP on both 
the router and the switch.  Make sure you have fairly recent code on the 
Catalyst.  We had a problem a while back where the router and the switch both 
believed that they were doing CGMP, and the switch listed which ports were 
active IP multicast participants, but flooded IP multicast packets to all 
ports anyway.  We are currently running

	McpSW: 2.4(3) NmpSW: 2.4(3)

on our switches, and they are working fine.

					/Chris