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

[Chuck Anderson]

Instead of LAG you can try RTG, redundant-trunk-group.  That would block ingress and egress traffic on the backup link and not require STP.

On Fri, Aug 17, 2018 at 11:20:24AM +0000, Javier Valero wrote:
> 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.