Multicast Scenario

[Pradyetendu Mohapatra]

Hi Folks, I have a customer scenario. Customer current environment is running PIM Dense mode on all routers and Layer 3 switches.

Customer is expanding his network where customer is adding new WAN routers (ISR 4000 series) which do not support PIM Dense mode.

Only option left is to run PIM Sparse mode. Customer do not want to change current setup from Dense to Sparse just to add new network.

Please suggest how I can integrate both networks.

[Hector Gustavo Serrano Gutierrez · Accepted solution]

Hello Pradyetendu Mohapatra,

As far as I know, ISRs 4400 & 4300 do support Multicast PIM sparse, dense & sparse-dense modes.

Additionally, some points to take into consideration are:

• The Sparse-Mode is a better choice to deploy Multicast PIM across the network because its operation is "flood on demand" vs  Dense mode's "flood & prune".

• Most Cisco Routers running Cisco IOS supports the use of Sparse-Dense-mode.

The Router will use either Sparse or Dense mode depending on the existence (or lack of existence) of a Rendezvous Point (RP) in the Router's configuration.

• Sparse-Dense-mode is not available on all Cisco platforms. For instance, NX-OS (Cisco Nexus family) does not have this option.

• You just need to add a RP in the Router's configuration when running Dense mode and change the Router's interface configuration to Sparse-mode to migrate.

• In Sparse-mode, it is important all Routers and L3 Switches agree in who the RP is for the network. Also, the method to propagate this information (static, Auto-RP or BSR).

I hope this helps.