The SM2 blocks downstream multicast Ethernet frames in MAC Forwarding mode. The only exception is multicast frames that are using IGMP. Therefore if you are using MAC Forwarding mode the OSPF Multicast frames are getting dropped. In VLAN Forwarding mode, where each customer has to have a unique VLAN, all Ethernet traffic, including Multicast and Broadcast frames will be forwarded through the SM2. Another thing to keep in mind should you be doing VLAN Forwarding in the SM2 is the MLPPP card for the TA3000 extracts the IP packet coming from the MLPPP link, puts it in an Ethernet frame with a learned destination MAC address of it's provisioned Gateway. So the MLPPP card does not send a multicast MAC addresses, which means the Gateway has to be able to do OSPF Point-to-Point.