Customize Broadcast and Multicast Handling Settings

Complete the Add a Network Policy task.

To reduce unnecessary airtime usage for multicast transmissions, a device can convert multicast frames to unicast frames under certain conditions or at all times, and can drop multicast frames when there are no group members present to receive them. Unicast traffic can increase the reliability of video delivery. If a wireless client does not receive a unicast frame and does not reply with an ACK, the AP will retransmit. Multicast traffic does not support wireless frame delivery confirmation.

This task is part of a series for configuring the Optional Settings for a standard wireless network. Use this task to customize settings for broadcast and multicast handling.

  1. Go to Configure > Network Policies.
  2. Select an existing policy, and then select Edit.
  3. Select Next to open the Wireless Network page.
  4. Go to Additional Settings > Optional Settings, and then select CUSTOMIZE.
  5. Go to the Broadcast and Multicast Handling section, and then select one of the following Convert IP Multicast to Unicast options:
    • Auto: The device is enabled to convert multicast frames to unicast when the channel utilization or membership count conditions are met.
    • Always: The device makes the conversion unconditionally.
    • Disable: The device does not use the multicast-to-unicast conversion feature, but instead follows the standard 802.11 behavior for sending multicast frames.
  6. Set the Channel Utilization Threshold from 1 to 100%.
  7. Set the Membership Count Threshold from 1 to 30.
  8. Select Enable Non-Essential Broadcast Filtering to reduce unnecessary broadcast and multicast traffic forwarding (such as AMRP, HSRP, LLC, and STP) from APs with no registered listeners.
  9. Select Enable Multicast Drop to drop multicast and broadcast traffic, excluding frames for any of the selected protocols. With the exception of MDNS, by default, all protocols are selected and are therefore included in multicast and broadcast traffic. To exclude protocols in multicast and broadcast traffic, proceed as follows:
    • DHCPv4: Clear the check-box to drop Dynamic Host Configuration Protocol version 4.
    • DHCPv6: Clear the check box to drop Dynamic Host Configuration Protocol version 6.
    • ARP: Clear the check box to drop Address Resolution Protocol.
    • IGMP-query: Clear the check box to drop Internet Group Management Protocol queries.
    • IPv6-Discovery: Clear the check box to drop Internet Control Message Protocol router discovery messages.
    • MDNS: This check box is not selected by default and is therefore preset to drop multicast DNS frames. Select this check box to include multicast DNS frames in multicast and broadcast traffic.

Continue configuring Optional Settings in the Wireless Networks configuration window. Select SAVE OPTIONAL SETTINGS to save your changes.

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