Administrator Guide
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
-4 103.103.103.3 --> Source
------------------------------------------------------------------
1034 Multicast