From: hong tony (aamercado31@xxxxxxxxx)
Date: Thu May 16 2002 - 19:36:16 GMT-3
On rereading my responce, I think I only answered it
indirectly...Let me try again,
Think of PIM Non-Broadcast Multi-Access mode as a type
of QOS. Multicast routing will work whether you have
NBMA Mode on or off but with it on, it is more
efficient...so it is encouraged that you use it so
replication is performed at optimal points in the
network.
Traditionally, cisco routers replicate
multicast/broadcast packets to all "broadcast"
configured neighbors. This can be inefficient when not
all neighbors want packets for certain multicast
groups.
NBMA-mode allows one to reduce bandwidth on links
leading into the NBMA network as well as CPU cycles in
switches and attached neighbors...so you need to have
nbma mode on all routers A,B,C,D.
HTH
--- Sam.MicroGate@usa.telekom.de wrote:
> Tony,
>
> This is understood. Please read my email to the end.
> My question was why my
> multipoint interface in the frame relay network is
> working without using the
> ip pim nbma-mode command?
>
> Sam
>
> -----Original Message-----
> From: hong tony [mailto:aamercado31@yahoo.com]
> Sent: Thursday, May 16, 2002 5:11 PM
> To: Sam.MicroGate@usa.telekom.de;
> ccielab@groupstudy.com
> Subject: Re: When should I use ip pim nbma-mode?
>
>
> HI
>
> If you have CCO login, try the command lookup tool:
>
http://www.cisco.com/support/Cmdlookup/ios-search.html
>
> If not, then u can still hit cisco web and drill
> down
> the web site by choosing Technical Documents, Cisco
> IOS software, 12.2 and Cisco IOS Release 12.2 Master
> Indexes,
>
> do a cntl-f to find and there you go
>
> Anyways, here's the snippet:
> When this command is configured, each Protocol
> Independent Multicast (PIM) Join message is kept
> track
> of in the outgoing interface list of a multicast
> routing table entry. Therefore, only PIM WAN
> neighbors
> that have joined for the group will get packets sent
> as data link unicasts. This command should only be
> used when the ip pim sparse-mode command is
> configured
> on the interface. This command is not recommended
> for
> LANs that have natural multicast capabilities.
>
>
> HTH
>
> --- Sam.MicroGate@usa.telekom.de wrote:
> > Hello everyone
> >
> > I have a frame relay hop and spoke topology. The
> hop
> > is multipoint and the
> > three spokes are physical interfaces. My IGP is
> > OSPF. Everything is working
> > fine. I configured the hop as static rp using the
> > command ip pim rp-address.
> > I issued the same command in all the routers in
> the
> > internetwork. Still
> > everything work fine. I ping all my multicast
> > sources and my multicast
> > routes show correctly in all the routers. Here is
> my
> > question, When should I
> > use ip pim nbma-mode? I read in one of the posting
> > that I must use this
> > command in multipoint interfaces for the multicast
> > to work correctly in the
> > frame relay environment. I did not use ip pim
> > nbma-mode in my multipoint
> > interface and still working. Do I really need it
> or
> > I did something wrong.
> > Thanks for your help.
> >
> > Sam
> >
>
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:58:58 GMT-3