From: Brian Hescock \(bhescock\) (bhescock@cisco.com)
Date: Thu Mar 29 2007 - 16:08:52 ART
Luca,
Hi, pim nbma-mode is for sparse mode, as indicated in the referenced
document further down in this thread.
<snip>
When using the ip pim nbma-mode command, note the following usage
guidelines:
This command applies to only PIM sparse mode configurations because its
functionality is dependent on the PIM sparse mode join message.
<snip>
With nbma-mode the router tracks each remote router on the multipoint
interface by ip address just as if they were on a separate
subinterfaces. You can prune from a given remote router and have no
impact on other remote routers off that same multipoint interface.
There is no need for a prune override per se in that circumstance,
although if you happen to see one in debugs it may be the IOS way of
overcoming it using nbma-mode.
I would suggest using the feedback mechanism in the left frame of the
web page if the documentation isn't clear. I've used it many times over
the years and have received a response each time.
Regards,
Brian
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Bit Gossip
Sent: Wednesday, March 28, 2007 12:38 PM
To: 'ccielab'
Subject: Re: multicast very fundamental
Antonio,
the document that you mention was also my orginal understanding; in
reality
though, things seem to work differently.
I don't know how much one can rely on this undocumented feature. Would
be
nice to have a comment from Cisco on this, as it is rather fundamental
.....
One approach could be: 'do as if this feature didn't exist'
Let's hope that someone from Cisco pick this up...
Luca.
----- Original Message -----
From: "Antonio Soares" <amsoares@netcabo.pt>
To: "'Bob Sinclair'" <bob@bobsinclair.net>; "'Bit Gossip'"
<bit.gossip@chello.nl>
Cc: "'ccielab'" <ccielab@groupstudy.com>
Sent: Wednesday, March 28, 2007 5:28 PM
Subject: RE: multicast very fundamental
Hello,
Very interesting discussion.
So may we assume that the Prune Override mechanism works the same way in
NBMA as in Broadcast Networks? And that the "ip pim nbma-mode" is only
an
optimization feature available with PIM-SM ?
If this is true, at least the document bellow should be updated (see
figure
3):
http://www.cisco.com/en/US/tech/tk828/technologies_white_paper09186a0080
0d6b
61.shtml#xtocid3
Thanks,
Antonio
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Bob
Sinclair
Sent: terga-feira, 27 de Margo de 2007 21:25
To: Bit Gossip
Cc: ccielab
Subject: Re: multicast very fundamental
Bit Gossip wrote:
> Happy to hear that I am not the only one to experience this 'behind
> the curtains' prune override.
> As a consequence of this behaviour, the only real benifit of 'ip pim
> nbma-mode' is:
> - efficiency in sending the group to only PVCs that really want it
> - performance in that in can be performed in CEF mode instead of
> process switch
>
I would add two additional benefits of nbma-mode: it permits
spoke-to-spoke
multicast, and permits a BSR to be on a spoke.
--Bob Sinclair CCIE 10427 CCSI 30427 www.netmasterclass.net
This archive was generated by hypermail 2.1.4 : Sun Apr 01 2007 - 06:35:53 ART