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Configuring MLD Snooping Tracing Operations on EX Series Switch VLANs (CLI Procedure)

By enabling tracing operations for MLD snooping, you can record detailed messages about the operation of the protocol, such as the various types of protocol packets sent and received. Table 1 describes the tracing operations you can enable and the flags used to specify them in the tracing configuration.

Table 1: Supported Tracing Operations for MLD Snooping

Tracing Operation


Trace all (equivalent of including all flags).


Trace client notifications.


Trace general MLD snooping protocol events.


Trace group operations.


Trace host notifications.


Trace leave reports.


Trace normal MLD snooping protocol events. If you do not specify this flag, only unusual or abnormal operations are traced.


Trace all MLD packets.


Trace policy processing.


Trace MLD membership query messages.


Trace membership reports.


Trace routing information.


Trace state transitions.


Trace routing protocol task processing.


Trace timer processing.


Configuring Tracing Operations

To configure tracing operations for MLD snooping:

  1. Configure the filename for the trace file:

    For example:

  2. (Optional) Configure the maximum number of trace files and size of the trace files:

    For example:

    causes the contents of the trace file to be emptied and archived in a .gz file when the file reaches 1 MB. Four archive files are maintained, the contents of which are rotated whenever the current active trace file is archived.

    If you omit this step, the maximum number of trace files defaults to 10, and the maximum file size to 128 KB.

  3. Specify one of the tracing flags shown in Table 1:

    For example, to perform trace operations on VLAN-related events and on MLD query messages:

Viewing, Stopping, and Restarting Tracing Operations

When you commit the configuration, tracing operations begin. You can view the trace file in the /var/log directory. For example:

You can stop and restart tracing operations by deactivating and reactivating the configuration: