Setup Guide

Usage
Information
After you enable multicast, you can enable IGMP and PIM on an interface. In INTERFACE mode, enter the
ip pim sparse-mode command to enable IGMP and PIM on the interface.
Related
Commands
● ip pim sparse-mode — enable IGMP and PIM on an interface.
mtrace
Trace a multicast route from the source to the receiver.
Syntax
mtrace [vrf vrf-name] {source-address/hostname} [destination-address/
hostname] [group-address/hostname]
Parameters
vrf vrf-name Enter the keyword vrf followed by the name of the VRF. If VRF name is not
mentioned, the default VRF will be used. Mtrace is not supported for management
VRF.
source-address/
hostname
Enter the source IP address in dotted decimal format (A.B.C.D). This is a unicast
address of the beginning of the path to be traced.
destination-
address/
hostname
Enter the destination (receiver) IP address in dotted decimal format (A.B.C.D). If
omitted, the mtrace starts from the system at which the command is typed.
group-address/
hostnamae
Enter the multicast group address in dotted decimal format (A.B.C.D). If group
address is not given then software shall invokes a weak mtrace. A weak mtrace
is one that follows the RPF path to the source, regardless of whether any router
along the path has multicast routing table state
Command Modes EXEC Privilege
Command
History
Version Description
9.11.0.0 Re-introduced the mtrace command on the Dell EMC Networking OS.
7.5.1.0 Expanded to support originator.
7.4.1.0 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 EMC Networking OS supports the Mtrace client and transit functionality.
As an Mtrace client, Dell EMC 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 EMC Networking OS returns the response to Mtrace
queries. After receiving the Mtrace request, Dell EMC 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
972 Multicast