Cisco Nexus 3064 Multicast traffic issue

[jethro.w.tambeana]

Hi there, I hope i am posting in the correct place. I need assistance with an issue which seems to be related to Multicast. I have a few Cisco 3064 connected in a ring and I wish to pass traffic for a local TV station over this link. i noticed that the TV traffic is not passing through however there is IP connectivity from source of the traffic to the destination, ping is successful and macs are visible at both ends. the Interface on one of the cisco 3064 on which the TV traffic comes in shows that traffic is coming into the switch however it seems that traffic is not flowing from that first cisco 3064 to the other switches.

Could this be an issue with Multicast? I enabled the PIM and MSDP feature on the switches however the status of both are enabled (not-running).

I need assistance with this.

[Christopher Hart · Accepted solution]

Hi Jethro,

You mentioned that PIM is enabled on the Nexus 3064, so I am assuming that this is routed multicast traffic. Can you confirm that a PIM RP address is configured on the switch, as well as PIM Sparse-Mode is enabled on all interfaces of the switch pointing towards multicast senders or receivers with the ip pim sparse-mode interface configuration command?

Thank you!

-Christopher

[jethro.w.tambeana]

Hi there, firstly thank you for your response. as for the multicast traffic, no it is not a routed multi-cast traffic. it is switched/L2 multi-cast traffic. a video encoder and decoder are connected to the network to carry video traffic and so traffic passes successfully through other cisco switches (cisco 2960) but when it gets to the nexus 3064 traffic is not going through.

below is traffic path

Video Encoder --> Cisco 2960 --> Cisco 2960 --> Nexus 3064 --> Nexus 3064 --> Nexus 3064 --> Cisco 2960 --> Video Decoder

[Sergiu.Daniluk · Accepted solution]

Hi @jethro.w.tambeana 

If you only have L2 multicast, then you have 3 options to make it work:

1. disable IGMP snooping on all switches in the path. The downside of this option is that mcast traffic will be flooded on interfaces where traffic is not needed, so not really the best option out to make this work.

2. (the recommended way) enable IGMP snooping on all switches in the path + enable IGMP snooping querier on one of the Nexus 3K. This is done per vlan basis and here is an example:

configure terminal
  ip igmp snooping
  vlan configuration <vlan-id>
    ip igmp snooping
    ip igmp snooping querier <querier-IP-address>

Stay safe,

Sergiu

[jethro.w.tambeana]

Thank you for that. I will apply the second option. regarding the <querier-IP-address>, given I have a video encoder (source of video traffic) and decoder, would the <querier-IP-address> be the multicast address for the video encoder? I just want to make sure i got that right.

[jethro.w.tambeana]

Hi Sergiu, i noticed that the option to configure the querier IP address is not there under vlan mode. see below.

FB-SW-08(config)# vlan 300
FB-SW-08(config-vlan)# ip igmp snooping

FB-SW-08(config-vlan)# ip igmp snooping ?
*** No matching command found in current mode, matching in (config) mode ***
<CR>
event-history Configure event-history buffers
link-local-groups-suppression Configures Global link-local groups
suppression
many-to-one-enhance Enable many to one optimization for n3500
platform
mrouter Configures static multicast router interface
optimise-multicast-flood Configures Optimized Multicast Flood (OMF) on
all VLANs
report-suppression Configures Global IGMPv1/IGMPv2 Report
Suppression
syslog-threshold IGMP SNOOPING table syslog threshold
v3-report-suppression Configures Global IGMPv3 Report Suppression
and Proxy Reporting

[Sergiu.Daniluk · Accepted solution]

Hi @jethro.w.tambeana 

Try under " vlan configuration <vlan-id>"

About the ip address of the querier, can be any IP address. Just make sure you do not overlap IP addresses.

Stay safe,

Sergiu