Multicast between switches - Same VLAN

[TimJenkins]

I have a VoIP solution that resides in a single VLAN and which requires Multicast for PTP Time synchronisation.  The PTP Master/Slave election is based on Serial number of each device so the Source or Receiver could theoretically be on any one of a number Access Switches & Ports.  2 x VoIP units plugged into the same switch, PTP works.

PTP multicast traffic seems to fail when traversing switches.  I've been through this guide which I think is the problem,  (https://www.cisco.com/c/en/us/support/docs/switches/catalyst-6500-series-switches/68131-cat-multicast-prob.html#anc30) however, from the 5 solutions listed in it......

Solution 1 - "ip pim sparese-dense-mode" isn't a valid command on an N5K
Solution 2 - "ip igmp snooping querier" isn't a valid command on an N5K
Solution 3 - "ip igmp snooping vlan......" command not available on N9K
Solution 4 - Doesn't look scalable
Solution 5 - Cisco recommendation on N9K is to not disable IGMP snooping.

Network Topology diagram below.   Any pointers since I'm scratching my head how to get this working? Thanks in advance.

[cmarva]

if by n5k you are talking nexus 5k, check and make sure that pim is enabled. do a sho run | incl feature to verify. i think that's the reason why you can't enable pim on the svi, 

[TimJenkins]

Ah yes, ta. No, it's not an enabled feature.  Will turn that on to see if it fixes the problem - many thanks

[Joseph W. Doherty]

If you switches are running IGMP snooping, they need a IGMP querier.  The querier is generally provided by the router doing multicast to the connected interface.  Enabling PIM, on the interface (ip pim passive), should do the trick.  NB: on Nexus platforms, you also often need to enable features for them to process their corresponding configuration settings.