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PIM SSM and Bi-Dir PIM?

I have two quick questions ...

What is the best use and reason for implementing PIM SSM?

What is the best use and reason for implementing Bi-Dir PIM?

Thank you!

6 REPLIES

Re: PIM SSM and Bi-Dir PIM?

Hi,

Bellow are the reasons:

Pim SSM: Cisco highly recommend the use of Data-mdt (SSM) to optimize multicast traffic and to support high multicast bandwidth applications. In Source Specific multicast , Hosts sends IGMP Source specific along with its group. The IGMP Query is send to the address (224.0.0.13).

Pim Bi-Dir: Pim Bi-directional is implemented in a Network which has sources that are also recievers for different Groups (In between). In Pim Bi-dir the source of the tree is rooted at the shared tree. Pim Designated Forwarder is elected based on the highest ip address on a segment, In Pim Bi-dir the Pim Register and Register-message is the removed to prevent added overhead.

HTH

Mohamed

Cisco Employee

Re: PIM SSM and Bi-Dir PIM?

Mohamed,

Just one clarification on the Designated Forwarder election (DF). The DF is elected based on

(1) the preference of its route to the RP.

(2) the metric of its route to the RP.

(3) Highest IP address (tie breaker)

Regards

Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México
Hall of Fame Super Silver

Re: PIM SSM and Bi-Dir PIM?

Hello Rashida,

Bi-Dir PIM is a good solution when there are multiple sources for the multicast groups in use the capability to build bidirectional trees provide more forwarding efficiency.

PIM SSM is source aware so it allows for security (do not propagate traffic from arbitrary ip addresses) and for reuse of multicast ip addresses: a different ip source is seen as a different session users with IGMP v3 request a group and can specify a source.

Hope to help

Giuseppe

Re: PIM SSM and Bi-Dir PIM?

Yes Harold Correct, I missed that ..

The prefrence "first" and the least metric toward the RP "secondly" and then the highest IP address.

Actually, the Designated Router in Pim Sparse mode is selected based on the highest IP address on a segment.

HTH

Mohamed

Cisco Employee

Re: PIM SSM and Bi-Dir PIM?

Hi Mohamed,

You are correct about the DR election. By the way, The DF election was based on the PIM assert mechanism.

Regards

Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México

PIM SSM and Bi-Dir PIM?

How to implement pim-ssm over mpls with sparse-mode and test by notebook from vlc player

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