Technical Documentation

Configuring Multicast Snooping Options (NSM Procedure)

Multicast snooping is a way for a Layer 2 device to snoop at the Layer 3 packet content to determine which actions are to be taken to process or forward a frame. There are specific forms of snooping, such as IGMP snooping or PIM snooping. In all cases, snooping involves a device configured to function at Layer 2 having access to Layer 3 (packet) information. Snooping makes multicasting more efficient in these devices.

To configure multicast snooping in NSM:

  1. In the navigation tree select Device Manager > Devices.
  2. In the Devices list, double click the device to select it.
  3. In the Configuration tab, expand Multicast Snooping Options.
  4. Add or modify the settings as specified in Table 1.
  5. Click one:
    • OK—To save the changes.
    • Cancel—To cancel the modifications.

Table 1: Multicast Snooping Options Configuration Details

Task Your Action

Establish a list of flood group addresses for multicast snooping.

  1. Click Flood Groups next to Multicast Snooping Options.
  2. Click Add new entry next to Flood Groups.
  3. In the dialog box, enter the IP addresses.

Configure multicast forwarding cache properties.

  1. Click Forwarding Cache next to Multicast Snooping Options.
  2. In the Comment box, enter the comments.
  3. Expand Forwarding Cache.
  4. Click Threshold next to Forwarding Cache.
  5. In the Comment box, enter the comments.
  6. From the Suppress list, select the threshold value for a forwarding cache.

    Range: 1 through 200,000

  7. From the Reuse list, select the reuse value for the threshold. The reuse value must be less than the suppression threshold value.

    Range: 1 through 200,000

Establish the graceful restart duration for multicast snooping.

  1. Click Graceful Restart next to Multicast Snooping Options.
  2. In the Comment box, enter the comments.
  3. From the Restart Duration list, select the duration for graceful restart.

    Range: 0 to 300 seconds

    Default : 180 seconds

Establish multicast snooping option values.

  1. Click Option next to Multicast Snooping Options.
  2. In the Comment box, enter the comments.
  3. Expand Options.
  4. Click Syslog next to Options.
  5. In the Comment box, enter the comments.
  6. From the Upto list, select select the level upto which severity the messages to be syslogged.
  7. From the Mark list, select the time interval in seconds to mark the trace file.

    Range : -2147483647 seconds to 2147483647 Seconds

    Default : 0

  8. Expand Syslog.
  9. Click Level next to Syslog.
  10. Select the Level of severity to be logged.

Configure tracing options.
  1. Click Traceoptions next to Multicast Snooping Options.
  2. In the Comment box, enter the comments.
  3. Expand Traceoptions.
  4. Click File next to Trace Options.
  5. In the Comment box, enter the comments.
  6. In the Filename box, enter the name of the file to receive the output of the tracing operation. Enclose the name within quotation marks.
  7. In the Size box, enter the maximum size of each trace file in bytes.

    Range : 10240 to 4294967295 bytes

  8. From the Files list, select the maximum number of files.
  9. Select the world-readable option to enable log file access to all users.
  10. Select the no-world-readable option to prevent all users from reading the log file.
  11. Click Flag next to Trace Options.
  12. Click Add new entry next to flag.
  13. From the Name list, select a tracing operation to perform.
  14. In the Comment box, enter the comments.

Published: 2009-08-23