mtrace v1

Use mtrace v1 to trace a multicast path through mtrace1.

Syntax

mtrace v1 [ vpn-instance vpn-instance-name ] { source-address | group-address } * [ destination address ] [ verbose ]

Views

Any view

Predefined user roles

network-admin

mdc-admin

Parameters

vpn-instance vpn-instance-name: Specifies an MPLS L3VPN instance by its name, a case-sensitive string of 1 to 31 characters. If you do not specify a VPN instance, this command traces a multicast path on the public network.

source-address: Specifies a multicast source by its IP address.

group-address: Specifies a multicast group by its IP address, in the range of 224.0.1.0 to 239.255.255.255.

destination address: Specifies the destination address of mtrace. The default destination address is 224.0.0.2.

verbose: Displays detailed information about mtrace. If you do not specify this keyword, the command displays brief information about mtrace.

Usage guidelines

To perform a non-group-specific mtrace, specify a multicast source and a destination. The mtrace starts from the destination and ends at the device directly connected to the multicast source.

To perform a non-source-specific mtrace, specify a multicast group and a destination. The mtrace starts from the destination and ends at the RP associated with the multicast group.

To perform a source-and-group-specific mtrace, specify both a multicast source and a multicast group. If you also specify a destination, the mtrace starts from the destination and ends at the device directly connected to the multicast source. If you do not specify a destination, the mtrace starts from the upstream device of the client and ends at the device directly connected to the multicast source.

An mtrace process stops if the number of traced hops reaches 255.

If the client does not receive a Reply message within 10 seconds, the client initiates a hop-by-hop mtrace to determine which device on the path encountered an error. It sends a Query message with the hops field set to 1 and waits for a Reply message. If it does not receive a Reply message within 10 seconds, the client determines that this hop encountered an error. If the client receives a Reply message within 10 seconds, it sends a Query message with the hops field value increased by 1 and waits for a Reply message. This process continues until the client does not receive a Reply message within the waiting time any more.

Examples

# Use mtrace1 to trace the path along which multicast data of group 225.2.1.1 travels from source 10.11.5.24 to destination 192.168.2.2 and display brief mtrace information.

<Sysname> mtrace v1 10.11.5.24 225.2.1.1 destination 192.168.2.2
 Mtrace from 10.11.5.24 to 192.168.2.2 via group 225.2.1.1, 255 hops at most, press 
CTRL_C to break.
 Querying full reverse path...

  Hop  Incoming address  Outgoing address  Protocol       Time    Fwd code
    0  5.1.1.2           192.168.2.1       PIM            50 s    NO_ERROR
   -1  4.1.1.2           5.1.1.1           PIM            40 s    NO_ERROR
   -2  3.1.1.2           4.1.1.1           PIM            60 s    NO_ERROR
   -3  2.1.1.2           3.1.1.1           PIM            55 s    NO_ERROR
   -4  10.11.5.1         2.1.1.1           PIM            30 s    NO_ERROR

Table 32: Command output

Field	Description
Hop	Number of the hop. 0 represents the last hop, -1 represents the hop before the last hop, and so on.
Incoming address	Incoming interface of the multicast data.
Outgoing address	Outgoing interface of the multicast data.
Protocol	Multicast routing protocol used between this device and the previous-hop device: PIM. PIM(STATIC)—PIM using a static multicast route. PIM(MBGP)—PIM using an MBGP route. PIM(ASSERT)—PIM in a state created by Assert processing.
Time	Length of time used to transmit an mtrace message between this device and the previous-hop device, in seconds.
Fwd code	Forwarding code or error code: NO_ERROR—No error. WRONG_IF—The interface on which the mtrace message arrives is not in the outgoing interface list of the multicast data. PRUNE_SENT—This device has sent a prune message to the upstream device. PRUNE_RCVD—This device has received a prune message from the downstream device. SCOPED—A multicast border is configured on the incoming interface or outgoing interface of the multicast data. NO_ROUTE—This device does not have any route for the source or the RP. WRONG_LAST_HOP—This device is not the proper last-hop device. REACHED_RP—This device is the RP for the (, G) multicast data. RPF_IF—The mtrace message arrived on the expected RPF interface for the multicast data. NO_MULTICAST—The mtrace message arrived on an interface that is not enabled with IP multicast. NO_SPACE*—No space is available for inserting a response data block in the packet.

# Use mtrace1 to trace the path along which multicast data of group 225.2.1.1 travels from source 10.11.5.24 to destination 192.168.2.2 and display detailed mtrace information.

<Sysname> mtrace v1 10.11.5.24 225.2.1.1 destination 192.168.2.2 verbose
 Mtrace from 10.11.5.24 to 192.168.2.2 via group 225.2.1.1, 255 hops at most, use query 
 ID 12345, client port 50001, press CTRL_C to break.
 Querying full reverse path..........
Switching to hop-by-hop mode, Current hops: 2

    0: Incoming interface address: 4.1.1.2
       Outgoing interface address: 5.1.1.1
       Upstream router address: 4.1.1.1
       Input multicast packets: 111
       Output multicast packets: 111
       Forwarded packets for the (S, G) pair: 22
       Multicast protocol in use: PIM
       Multicast TTL threshold: 1
       Forwarding code: NO_ERROR
       Time used (s): 50

   -1: Incoming interface address: 3.1.1.2
       Outgoing interface address: 4.1.1.1
       Upstream router address: 3.1.1.1
       Input multicast packets: 111
       Output multicast packets: 111
       Forwarded Packets for the (S, G) pair: 22
       Multicast protocol in use: PIM
       Multicast TTL threshold: 1
       Forwarding code: NO_ERROR
       Time used (s): 50

Table 33: Command output

Field	Description
n	Number of the hop. 0 represents the last hop, -1 represents the hop before the last hop, and so on.
Incoming interface address	Incoming interface of the multicast data.
Outgoing interface address	Outgoing interface of the multicast data.
Upstream router address	IP address of the upstream device.
Input multicast packets	Statistics for packets received on the incoming interface of the multicast data.
Output multicast packets	Statistics for packets forwarded through the outgoing interface of the multicast data.
Forwarded packets for the (S, G) pair	Statistics for forwarded (S, G) packets.
Multicast protocol in use	Multicast routing protocol used on the traced path: PIM. PIM(STATIC)—PIM using a static multicast route. PIM(MBGP)—PIM using an MBGP route. PIM(ASSERT)—PIM in a state created by Assert processing.
Multicast TTL threshold	Maximum number of hops to be traced on the interface.
Forwarding code	Forwarding code or error code: NO_ERROR—No error. WRONG_IF—The interface on which the mtrace message arrives is not in the outgoing interface list of the multicast data. PRUNE_SENT—This device has sent a prune message to the upstream device. PRUNE_RCVD—This device has received a prune message from the downstream device. SCOPED—A multicast border is configured on the incoming interface or outgoing interface of the multicast data. NO_ROUTE—This device does not have any route for the source or the RP. WRONG_LAST_HOP—This device is not the proper last-hop device. REACHED_RP—This device is the RP for the (, G) multicast data. RPF_IF—The mtrace message arrived on the expected RPF interface for the multicast data. NO_MULTICAST—The mtrace message arrived on an interface that is not enabled with IP multicast. NO_SPACE*—No space is available for inserting a response data block in the packet.
Time used (s)	Length of time for transmitting the mtrace message from the previous-hop device to this device.

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