Log message indicates Malformed or Unhandled IP Packets dropped
Malformed or Unhandled IP Packets will occur if you are using SonicOS standard firmware and there is a multi-casting device on the network. SonicOS Standard firmware cannot handle multicasting and will generate these errors. These errors were previously hidden and only displayed during debugging. You can try setting the WAN MTU to 1452 and allowed fragmented packets over VPN.
If you are running SonicOS Enhanced (which does handle multicasting), then the problem may be with an upstream device on the network.
Additional information: Protocol 2 is IGMP, which is a session-layer protocol that is used to manage multicast groups. When a host wants to join a specific multicast group, it sends a Membership Report to notify the gateway that it is listening on a specific multicast address.
If Remote Services are enabled on a Windows machine, it will send an IGMP Membership Report to the 'all routers multicast group' 18.104.22.168 when it comes online. If Multicast support is not enabled on the interface, the SonicWall will drop this packet and log the message "Malformed or unhandled IP Packet dropped, IP Protocol 2". To enable Multicast support on an interface, check the Enable Multicast Support box in the Interface configuration under the Advanced tab. (Enhanced firmware only)