You can now
enable buffering of the first packet in a multicast session
when the multicast route or forwarding information base (FIB) entry does not, yet, exist for the corresponding multicast group. By default, the firewall does not buffer the first multicast packet in a new session; instead, it uses the first packet to set up the multicast route. This is expected behavior for multicast traffic. You need to enable multicast route setup buffering only if your content servers are directly connected to the firewall and your custom application cannot withstand the first packet in the session being dropped.