RE: RE: PIM sparse or sparse-dense with PIM NBMA mode?

From: Brian Dennis (bdennis@internetworkexpert.com)
Date: Fri Jul 22 2005 - 17:54:30 GMT-3


Jeremy,
        You can run sparse-dense mode with PIM NBMA without any
problems. The message that is displayed when you apply PIM NBMA mode to
an interface configured as sparse-dense is basically telling you that
PIM NBMA mode does not work for the dense mode traffic. It would create
a lot less confusion if Cisco wouldn't have had the message when PIM
NBMA mode is applied to the interface say "PIM nbma-mode is not
recommended for sparse-dense-mode" but say that "PIM nbma-mode will only
work for the sparse mode multicast traffic".

        In the IEATC-RS class and the IEATC-RS Class-on-Demand I spend
about an hour and a half covering Auto-RP in a hub and spoke environment
since it's definitely one of the areas must students aren't comfortable
with.

Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
bdennis@internetworkexpert.com
 
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987
Direct: 775-745-6404 (Outside the US and Canada)

 -----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Jeremy
Sent: Friday, July 22, 2005 1:02 PM
To: Chris Lewis (chrlewis); ccielab@groupstudy.com
Subject: Re: RE: PIM sparse or sparse-dense with PIM NBMA mode?

Thanks, Chris! There it is....ip pim autorp listener

It sure helps to know where to look sometimes.

-Jeremy

From: "Chris Lewis \(chrlewis\)" <chrlewis@cisco.com>
Date: 2005/07/22 Fri PM 01:25:07 EDT
To: "Jeremy" <jeremy19@cox.net>, <ccielab@groupstudy.com>
Subject: RE: PIM sparse or sparse-dense with PIM NBMA mode?

There is a way to run auto-rp and enable just sparse-mode on the
interfaces.

Have a look at the command reference for multicast at
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123cgcr/
iprmc_r/ip3_i2g.htm

If you search for autorp, you should find what you are looking for.

Chris

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Jeremy
Sent: Friday, July 22, 2005 9:55 AM
To: ccielab@groupstudy.com
Subject: PIM sparse or sparse-dense with PIM NBMA mode?

I have the following setup: R3, R4, and R5 are connected to a
frame-relay hub-and-spoke network with R3 as the hub, connected via
physical interfaces. I have attempted a diagram below.

VLAN5-----[R5]--\
                 \
                (F/R)---[R3]
                 /
VLAN47----[R4]--/

A previous requirement was for R3 to be the mapping agent for R6, which
lies beyond R3. This pointed met to auto-rp, which requires
sparse-dense mode for groups 224.0.1.39 and 224.0.1.40 in order to work
(right?).

A later requirement stated that R5 starts receiving traffic destined for
R4 (VLAN 47) and vice versa (R4 is receiving traffic for R5 or VLAN 5),
and that this behavior needs to be fixed so that R4 only receives
multicast traffic destined for VLAN 47 and R5 only receives multicast
traffic destined for vlan 5.

The solution was to enable ip pim nbma mode on R3's serial interface.

My question is two-fold:

1) Is this configuration valid, and
2) If you run pim nbma mode (and consequently pim sparse mode), can you
still use auto-rp, or are these two technologies mutually exclusive?!?

-Jeremy



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