Optimized multicast forwarding with a cache

The techniques describe forwarding multicast traffic using a multi-level cache in a network device forwarding plane for determining a set of outgoing interfaces of the network device on which to forward the multicast traffic. For example, a multi-level cache is configured to store a multicast identifier of a multicast packet and multicast forwarding information associated with the multicast identifier, such as identification of one or more egress packet processors of the network device to which the multicast packet is to be sent for forwarding to the set of one or more egress network devices, and/or outgoing interfaces of the network device toward each egress network device of the set of one or more egress network devices. The multi-level cache is also configured to store respective multicast identifiers that are to be encapsulated with outgoing multicast packets that are forwarded to the set of one or more egress network devices.