RE: PIM-SM

From: TAN CHOH KOON (tckoon@pc.jaring.my)
Date: Mon Aug 09 2004 - 10:46:31 GMT-3


Hi Chris,

Answer is if you do not configure static RP for group 224.3.3.3, it
automatically fall to Dense Mode.
If you configure static RP for group 224.3.3.3, but let say the RP address
is non existing in your network. 224.3.3.3 will never fall to DM.
Configure interface with only Sparse Mode, do not mean it will never fall to
Dense Mode.
It depend on your Group mode. If your configure static RP for that gorup it
will never fall back to DM.
Even the RP is down or not existing !!

If you able to access to Networker 2003 slide, refer to Deploying IP
Multicast.

Extract from slide
-------------------

Group Mode vs. Interface Mode

 Group & Interface mode are independent.
 Interface Mode
 Determines how the interface operates when sending/receiving multicast
traffic.
Group Mode
 Determines whether the group is Sparse or Dense.

Group Mode
 Group mode is controlled by local RP info
 Local RP Information
 Stored in the Group-to-RP Mapping Cache
 May be statically configured or learned via
Auto-RP or BSR
 If RP info exists, Group = Sparse
 If RP info does not exist, Group = Dense
 Mode Changes are automatic.
i.e. if RP info is lost, Group falls back to Dense.

Configuring Interface
 Interface Mode Configuration Commands
 Enables multicast forwarding on the interface.
 Controls the interfaces interfaces mode of operation.
ip pim dense-mode
 Interface mode is set to Dense mode operation.
ip pim sparse-mode
 Interface mode is set to Sparse mode operation.
ip pim sparse-dense-mode
 Interface mode is determined by the Group mode.
 If Group is Dense, interface operates in Dense mode.
 If Group is Sparse, interface operates in Sparse mode.

Regards



This archive was generated by hypermail 2.1.4 : Fri Sep 03 2004 - 07:02:35 GMT-3