Enable Multicast Routing

Enabling multicast routing on the threat defense device, enables IGMP and PIM on all interfaces by default. IGMP is used to learn whether members of a group are present on directly attached subnets. Hosts join multicast groups by sending IGMP report messages. PIM is used to maintain forwarding tables to forward multicast datagrams.

Note

Only the UDP transport layer is supported for multicast routing.

The following list shows the maximum number of entries for specific multicast tables. Once these limits are reached, any new entries are discarded.

  • MFIB—30,000

  • IGMP Groups—30,000

  • PIM Routes—72,000

Procedure

Step 1

Choose Devices > Device Management, and edit the threat defense device.

Step 2

Choose Routing > Multicast Routing > IGMP.

Step 3

Check the Enable Multicast Routing check box.

Checking this check box enables IP multicast routing on the device. Unchecking this check box disables IP multicast routing. By default, multicast is disabled. Enabling multicast routing enables multicast on all interfaces.

You can disable multicast on a per-interface basis. This is useful if you know that there are no multicast hosts on a specific interface and you want to prevent the threat defense device from sending host query messages on that interface.