Efficient reverse path forwarding check mechanism
AssigneeLucent Technologies Inc.
InventorsJuan Diego Sanchez, Apurva Mehta
Life of this patent
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Abstract
An efficient Reverse Path Forwarding (RPF) check mechanism is disclosed. In one embodiment, when a network node receives a multicast packet on an incoming interface, the network node obtains an expected incoming interface identifier from either a unicast routing table or a multicast forwarding information table. A RPF Flag stored in association with multicast flow information determines from which table the interface identifier is obtained. If the expected incoming interface does not match the actual incoming interface, the multicast packet is discarded.
Claims27
A method for performing a Reverse Path Forwarding (RPF) check, comprising:
- receiving a multicast packet via an interface of a network node;
- obtaining an expected incoming interface identifier for the multicast packet from one of a plurality of locations including a unicast routing table and a multicast forwarding information table;
- and
- comparing the expected incoming interface identifier with an identifier for the interface.
A network node capable of multicasting, comprising:
- means for receiving a multicast packet via an interface of a network node;
- means for obtaining an expected incoming interface identifier for the multicast packet from one of a plurality of locations including a unicast routing table and a multicast forwarding information table;
- and
- means for comparing the expected incoming interface identifier with an identifier for the interface.
A network node capable of multicasting, comprising:
- a plurality of interfaces;
- a first circuit coupled to the interfaces and configured to receive a stream of multicast packets, wherein the first circuit, upon receiving a multicast packet via a first one of the interfaces, obtains an expected incoming interface identifier for the multicast packet from one of a plurality of locations including a unicast routing table and a multicast forwarding information table according to at least in part a state of the stream of multicast packets;
- and
- a second circuit coupled to the first circuit and configured to compare the expected incoming interface identifier with an identifier for the first interface.
Dependencies are inferred from the claim text.