The IGMP/MLD Screen
Use this screen to configure multicast groups that the Zyxel Device manages through IGMP/MLD settings. To open this screen, click Network Setting > IGMP/MLD.
*Some models might only support IGMP/MLD Default Version configuration.
Network Setting > IGMP/MLD
The following table describes the labels in this screen.
Network Setting > IGMP/MLD 
Label
Description
IGMP/MLD Configuration
Default Version
Enter the version of IGMP (1~3) and MLD (1~2) that you want the Zyxel Device to use on the WAN.
Query Interval
Enter the number of seconds the Zyxel Device sends a query message to hosts to get the group membership information.
Query Response Interval
Enter the maximum number of seconds the Zyxel Device can wait for receiving a General Query message. Multicast routers use general queries to learn which multicast groups have members.
Last Member Query Interval
Enter the maximum number of seconds the Zyxel Device can wait for receiving a response to a Group-Specific Query message. Multicast routers use group-specific queries to learn whether any member remains in a specific multicast group.
Robustness Value
Enter the number of times (1~7) the Zyxel Device can resend a packet if packet loss occurs due to network congestion.
Maximum Multicast Groups
Enter a number to limit the number of multicast groups an interface on the Zyxel Device is allowed to join. Once a multicast member is registered in the specified number of multicast groups, any new IGMP or MLD join report frames are dropped by the interface.
Maximum Multicast Data Sources(for IGMPv3)
Enter a number to limit the number of multicast data sources (1-24) a multicast group is allowed to have.
*The setting only works for IGMPv3 and MLDv2.
Maximum Multicast Group Members
Enter a number to limit the number of multicast members a multicast group can have.
Fast Leave Enable
Select this option to set the Zyxel Device to remove a port from the multicast tree immediately (without sending an IGMP or MLD membership query message) once it receives an IGMP or MLD leave message. This is helpful if a user wants to quickly change a TV channel (multicast group change) especially for IPTV applications.
LAN to LAN (Intra LAN) Multicast Enable
Select this to enable LAN to LAN IGMP snooping capability.
Membership Join Immediate (IPTV)
Select this to have the Zyxel Device add a host to a multicast group immediately once the Zyxel Device receives an IGMP or MLD join message.
Cancel
Click Cancel to exit this screen without saving.
Apply
Click Apply to save your changes back to the Zyxel Device.