Trigger a Layer 2 Tracemroute

Use this procedure to debug the IP Multicast over Fabric Connect stream path using l2 tracemroute on the VLAN (Layer 2) or the VRF (Layer 3). This procedure queries the SPBM multicast module to determine the B-VLAN, I-SID and nickname for the S and G streams. The nickname and I-SID are used to create a multicast MAC address.

Note

The VLAN option is only valid for a VLAN that has an I-SID configured and IGMP snooping enabled.

Before you begin

On the source and destination nodes, you must configure an autogenerated or an explicit CFM MD, MA, and MEP.
Enable the MEP.
Assign a nodal MEP to the B-VLAN.

Procedure

To enter User EXEC mode, log on to the switch.
Trigger a Layer 2 tracemroute on the VLAN:

l2 tracemroute source <A.B.C.D> group <A.B.C.D> vlan <1-4059>[priority <0–7>] [ttl—value <1–255>]

Note

For the preceding command, if you do not specify a VLAN, l2 tracemroute uses the global default VRF.

Wait for the l2 tracemroute to complete or press any key to abort.
Trigger a Layer 2 tracemroute on the VRF:

l2 tracemroute source <A.B.C.D> group <A.B.C.D> vrf WORD<1–16> [priority <0–7>] [ttl—value <1–255>]

Note

For the preceding command, if you do not specify a VRF, l2 tracemroute uses the global default VRF.

Wait for the l2 tracemroute to complete or press any key to abort.

Examples

The following is a sample output for a Layer 2 tracemroute on a VLAN:

Switch:1>enable
Switch:1#configure terminal
Switch:1(config)#l2 tracemroute source 192.0.2.81 233.252.0.1 vlan 201

Please wait for l2 tracemroute to complete or press any key to abort.

Source 192.0.2.81

Group: 233.252.0.1

VLAN:201

BMAC: 03:00:03:f4:24:01

B-VLAN: 10

I-SID: 16000001

===============================================================
1 PETER4 00:03:00:00:00:00 -> LEE1 00:14:0d:bf:a3:df
2 LEE1 00:14:0d:bf:a3:df -> LEE2 00:15:e8:b8:a3:df

The following is a sample output for a Layer 2 tracemroute on a VRF:

Switch:1>enable
Switch:1#configure terminal
Switch:1(config)#l2 tracemroute source 192.0.2.10 group 233.252.0.1 vrf red

Please wait for l2 tracemroute to complete or press any key to abort.

Source 192.0.2.10

Group: 233.252.0.1

VRF: redID 1

BMAC: 03:00:04:f4:24:01

B-VLAN: 20

I-SID: 16000001

===============================================================
1 PETER4 00:03:00:00:00:00 -> LEE1 00:14:0d:bf:a3:df
2 LEE1 00:14:0d:bf:a3:df -> LEE2 00:15:e8:b8:a3:df

Variable Definitions

The following table defines parameters for the l2 tracemroute command.


Variable	Value
source `<A.B.C.D>`	Specifies the source IP address.
group `<A.B.C.D>`	Specifies the IP address of the multicast group.
vlan `<1–4084>`	Specifies the VLAN value.
vrf `WORD<1–16>`	Specifies the VRF name. If you do not specify a VRF name, then the results are shown for the flow in the Global Router (default) context.
priority `<0–7>`	Specifies the priority value.
ttl `<1–255>`	Specifies the time-to-live (TTL) for the trace packet, which is how many hops the trace packet takes before it is dropped.