Method and apparatus for performing multicast traces in MPLS networks
View Patent ↗A multicast path trace capability is provided for tracing a multicast path from a root node to a leaf node where the trace originates at the leaf node. The leaf node sends a multicast trace request to the root node. The root node receives the multicast trace request and initiates a path trace request for collecting path information associated with the multicast path. The root node receives at least one path trace response, in response to the path trace request, which includes path information associated with the multicast path. The root node sends a multicast trace response, including the collected path information, to the leaf node. The leaf node receives the multicast trace response including the path information. The leaf node derives end-to-end path information for the multicast path using the path information received in the multicast trace response. The multicast path trace capability may be used for tracing an MPLS multicast path (e.g., a P2MP LSP) from a root node to a leaf node of the MPLS multicast tree. The multicast path trace capability may be used for tracing multicast paths in other types of multicast networks.
1. A method for tracing a multicast path between a root node and a leaf node of a multicast tree in a multicast network, the method comprising:
receiving, at the root node, a multicast trace request comprising an indication of a request by the leaf node for the root node to initiate tracing of the multicast path from the root node to the leaf node;
initiating, from the root node based on the multicast trace request, a path trace request adapted for tracing the multicast path from the root node to the leaf node;
receiving, at the root node, at least one path trace response associated with the path trace request, wherein the path trace response comprises path information associated with the multicast path; and
propagating a multicast trace response toward the leaf node, wherein the multicast trace response includes at least a portion of the path information from the at least one path trace response.
2. The method of claim 1 , wherein the multicast trace request comprises an Internet Group Management Protocol (IGMP) Message Type indicative that the multicast trace request is an mtrace request for a Point-to-Multipoint (P2MP) Multiprotocol Label Switching (MPLS) network.
3. The method of claim 1 , wherein the path trace request initiated from the root node is a request for a Point-to-Multipoint (P2MP) Label Switched Path (LSP)-Trace.
4. The method of claim 3 , wherein the P2MP LSP-Trace includes a Target Forwarding Equivalence Class (FEC) Stack TLV adapted for indicating to a transit node of the multicast path that the root node is requesting packet statistics associated with the multicast path.
5. The method of claim 1 , wherein the path information comprises at least one of hop information and packet statistics.
6. The method of claim 1 , wherein the multicast trace response comprises an Internet Group Management Protocol (IGMP) Message Type indicative that the multicast trace response is an mtrace response for a Point-to-Multipoint (P2MP) Multiprotocol Label Switching (MPLS) network.
7. The method of claim 1 , wherein the network is a Multiprotocol Label Switching (MPLS) network, wherein the multicast path is a Point-to-Multipoint (P2MP) Label Switched Path (LSP).
8. An apparatus for tracing a multicast path between a root node and a leaf node of a multicast tree in a multicast network, comprising:
a processor and a memory communicatively connected to the processor, the processor configured for:
receiving, at the root node, a multicast trace request comprising an indication of a request by the leaf node for the root node to initiate tracing of the multicast path from the root node to the leaf node;
initiating, from the root node based on the multicast trace request, a path trace request adapted for tracing the multicast path from the root node to the leaf node;
receiving, at the root node, at least one path trace response associated with the path trace request, wherein the path trace response comprises path information associated with the multicast path; and
propagating a multicast trace response toward the leaf node, wherein the multicast trace response includes at least a portion of the path information from the at least one path trace response.