Configuring Multicasting on a 2960x

[molearchik]

Hi,

Can anyone point me in the correct direction on how to set up multicasting on the 2960x switches? On other switches in our network, all we had to do to get this to work was to put the following commands on the vlans:

ip pim sparse-dense-mode

ip cgmp

and then also ip multicast-routing 

In the 2960x switches, these commands are not available. 

Help would be appreciated.

M.

[Josh Sprang · Accepted solution]

Are you routing on the 2960-X?  Typically these are only deployed as layer 2 switches and will not need multicast routing.  Layer 2 multicast is igmp snooping.  This only forwards multicast messages to switchports that send igmp reports to the router. 

Here is the configuration guide for igmp snooping be aware it is enabled by default:

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960x/software/15-2_3_e/multicast/configuration_guide/b_mc_1523e_2960x_cg/b_mc_1522e_2960x_cg_chapter_010.html

if you are running routing n the 2960x with the sdm prefer routing command it looks like multicast routing is omitted from the configuration guides so my guess is it is not supported.  Typically on a L3 switch you will need the following:

ip multicast routing dist (enables multicast routing)

<per interface you need PIM on>

ip pim sparse-mode <or> ip pim sparse-dense-mode

CGMP is legacy and IGMP should be used.  IGMP is enabled on any interface you enable PIM on at Layer 3. 

configuration guide on a 3750-X

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750x_3560x/software/release/15-2_3_e/multicast/configuration_guide/b_mc_1523e_3750x_3560x_cg/b_mc_3750x_3560x_chapter_010.html

hth

[molearchik]

Hi Josh,

 I do not believe we are routing with the 2960x devices. I checked igmp snooping and it is on. 

And I just found that on one of the newer switches that is doing routing that it was missing the ip multicast routing dist command. Once i turned that on, one of my locations started multicasting. So I think i'm on the right trail now.

Thank you!

Mary