The GRE tunnel itself should pass multicast, allowing OSPF to run on it.
But that only handles multicast ...on a single interface.
You also have to enable multicast routing between interfaces by configuring igmp-proxy on them
The GRE tunnel itself should pass multicast, allowing OSPF to run on it.
But that only handles multicast ...on a single interface.
You also have to enable multicast routing between interfaces by configuring igmp-proxy on them