This is expected behavior. IP multicast is treated as routed traffic hence TTL is decremented irrespective of whether it is transported over L2VSN or L3VSN. The minimum recommended TTL value is 4 for IP multicast to work on MCoSPB. TTL will be decremented twice once at ingress BEB and once at egress BEB on BRCM based ASICs. Ingress multicast BEB will not modify the TTL on any product or release.