Dell S3100 Command Line Reference Guide for the Series 9.112.0P2 - Page 1061

the RPF path to the source, regardless of whether any router along the path has multicast routing table state Command Modes Command History EXEC Privilege Version 9.11.0.0 7.5.1.0 7.4.1.0 Description Re-introduced the mtrace command on the Dell Networking OS. Expanded to support originator. Expanded to support the intermediate (transit) router. Usage Information Mtrace is an IGMP based protocol that provides a multicast trace route facility and is implemented according to the IETF draft "A trace route facility for IP Multicast" (draft-fenner-traceroute-ipm-01.txt). Dell Networking OS supports the Mtrace client and transit functionality. As an Mtrace client, Dell Networking OS transmits Mtrace queries, receives, parses, and prints out the details in the response packet received. A transit or intermediate router, forwards mtrace requests to the RPF neighbor after appending its response block to the packet. In case it is the first hop router, it sends a response. As an Mtrace transit or intermediate router, Dell Networking OS returns the response to Mtrace queries. After receiving the Mtrace request, Dell Networking OS computes the RPF neighbor for the source, fills in the request and the forwards the request to the RPF neighbor. Example R1>mtrace 103.103.103.3 1.1.1.1 226.0.0.3 Type Ctrl-C to abort. Querying reverse path for source 103.103.103.3 to destination 1.1.1.1 via group 226.0.0.3 From source (?) to destination (?) |Hop| OIF IP |Proto| Forwarding Code |Source Network/Mask| 0 1.1.1.1 --> Destination -1 1.1.1.1 PIM Reached RP/Core 103.103.103.0/24 -2 101.101.101.102 PIM - 103.103.103.0/24 -3 2.2.2.1 PIM - 103.103.103.0/24 -4 103.103.103.3 --> Source The mtrace command traverses the path of the response data block in the reverse direction of the multicast data traffic. The mtrace command traverses the reverse path to the source from the destination. As a result, the tabular output of the mtrace command displays the destination details in the first row, followed by the RPF router details along the path in the consequent rows, and finally the source details in the last row. The tabular output contains the following columns: • Hop - a hop number(counted negatively to indicate reverse-path) • OIF IP - outgoing interface address • Proto - multicast routing protocol • Forwarding code - error code as present in the response blocks • Source Network/Mask - source mask Multicast 1061