Mutlicast

[Ziggy74]

Hello all experts,

i'm experiencing an issue on the scenario in attached file , i have one server multicast that is connected to a sw1 in access port , Sw1 is connected to a router by a TR port , SW2 is also connected to the router by TR port , my IP receiver is connected to a SW2 port access  but it cannot lock the multicast.

Do you have any suggestion how to configure the SWs or router for this scenario?

Router is ASR

SW1 and SW2 are Nexus

Thanks in advance 

regards

[Giuseppe Larosa · Accepted solution]

Hello Ziggy74,

from the network diagram we see that all the devices including the multicast source and the receiver are in Vlan 30.

Here, the two switches SW1 and SW2 are likely using IGMP snooping to optimize forwarding of IPv4 multicast traffic to avoid to treat multicast frames as broadcast.

However, in order to make IGMP snooping happy, someone has to send IGMP queries in order to understand that there is a receiver for the multicast stream by sniffing = snooping IGMP reports from the receiver.

Usually this can be achieved by enabling IP multicast routing on the router and then enabling ip pim sparse-dense mode on the L3 interface associated to Vlan 30 (on ASR1000 it might be a BVI interface).

When PIM is enabled on an interface also IGMP version 2 is enabled on it.

In alternative one of SW1 or SW2 could be configured to act as an IGMP snooping querier: that is to send out IGMP periodic queries. (note only one should be configured for this).

With the first solution making the router a multicast router you will be able to have receivers in different Vlans then the one where the source is connected to.

Hope to help

Giuseppe

[Ziggy74]

Thanks Giuseppe!!Fixed