Pim Sparse dense mode with sparse mode

[animesh.khare]

Hi All

I need to design a new multicast solution on my network where I have decided to run Pim Sparse mode , but some part of the network interfaces are already configured with pim sparse-dense mode, so will there be any issues if some of my interfaces are running in Sparse mode and some are in sparse-dense mode.

Thanks

Animesh

[chrihussey]

I don't think this would be an issue. I have run networks in the same situation and never had problems. Once you've fully implemented the sparse mode design it would probably be a good idea to make all interfaces sparse only just to keep things clean.

[animesh.khare]

Thanks

Also in L3 switches do I need to put "ip multicast-routing distributed" or just "ip multicast-routing distributed" will do the same on cisco L3 switches ?

[chrihussey]

Not exactly sure what you are asking, but anything that is participating in the routing of the multicast needs to have multicast routing enabled and that would include L3 switches.

Some platforms require the "ip multicast-routing distributed" and others might not require the distributed. With regard to this, the distributed extension only has relevance local to the device and not other devices.

[animesh.khare]

let me reframe my question

On what Cisco routers/switches we need "ip multicast-routing distributed"

distributed keyword...

[paul driver]

Hello

Please review this:

Prior to multicast distributed switching, IP multicast traffic was always switched at the Route Processor (RP) in the Route Switch Processor (RSP)-based platforms. Starting with Cisco IOS Release 11.2 GS, IP multicast traffic can be distributed switched on RSP-based platforms with VIPs. Furthermore, MDS is the only multicast switching method on the Cisco 12000 Gigabit Switch Router (GSR), starting with Cisco IOS Release 11.2(11)GS.

Switching multicast traffic at the RP had the following disadvantages:

•The load on the RP increased. This affected important route updates and calculations (for BGP, among others) and could stall the router if the multicast load was substantial.

•The net multicast performance was limited to what a single RP could switch.

MDS solves these problems by performing distributed switching of multicast packets received at the line cards (VIPs in the case of RSP, and line cards in the case of GSR). The line card is the interface card that houses the VIPs (in the case of RSP) and the GSR line card (in the case of GSR). MDS is accomplished using a forwarding data structure called a Multicast Forwarding Information Base (MFIB), which is a subset of the routing table. A copy of MFIB runs on each line card and is always kept up to date with the MFIB table of the RP.

In the case of RSP, packets received on non-VIP IPs are switched by the RP.

MDS can work in conjunction with Cisco Express Forwarding (CEF), unicast distributed fast switching (DFS), or flow switching.

[animesh.khare]

Hi Paul ,

I understood what is MDS , but I want to know on every cisco routers/switches do I need to put "ip multicast-routing distributed" command to enable MDS , or just "ip multicast-routing" will enable MDS as well.

thanks