[j-nsp] Multicast duplicated on LAG with link-protection

[Javier Valero]

Hello all,

We are facing a problem with one customer and multicast video streams on a link aggregation.
Maybe someone in the list know this behaviour and how to solve it.

We have EX4550 (VC) switches on different sites. We transport our customer traffic over all our sites with a SVLAN assigned for them (QinQ) and give them multiple access points in different places.
In their service, they transmit some video streams with multicast, to all their sites. (IPTV)

In one place, we connect with the customer with two 10G ports, each one from a different equipment in our side (geographically), for redundancy.
In their side it is only one equipment (also an EX4550).

We cannot configure a link aggregation in our side, as they are different equipments. MC-LAG is not supported by EX4550.
But our customer can configure a link aggregation in link-protection mode. By this way, the avoid the use of STP for loop prevention.
In link-protection mode, the backup interface stays in standby mode, without egress traffic, but allowing ingress traffic.

The problem is the multicast traffic. As it is distributed over all the links, we send the traffic on both 10G interfaces.
The problem is that the backup interface of the link-proteccion is also accepting the multicast traffic, so in the customer equipment, they have the multicast duplicated.

This is causing problems on the customer side.

We don't know if the LAG is a good solution for this case, or we should tell our customer that use STP.
Maybe it is as simple as some configuration option that we don't know, or any filter that can be applicated only on the interface not active.

Someone have any idea how to solve this?

Thank you very much in advance.

Best regards.
Javier Valero.