3Com WX4400 Reference Manual page 225

The router and receiver ports that the WX learns based on multicast
traffic age out if they are unused. If necessary, you can statically
configure multicast router ports or multicast receiver ports on the WX.
You can only add network ports as static multicast router ports or
multicast receiver ports. Ports you add are immediately added to the list
and do not age out.
You cannot add MAP ports or wired authentication ports as static
multicast ports. However, MSS can dynamically add these port types to
the list of multicast ports based on multicast traffic.
To add or remove static multicast router and receiver ports:
1 Access the VLAN table:
a Select the Configuration tool bar option.
b In the Organizer panel, click the plus sign next to the WX switch.
c Click the plus sign next to System.
d Select VLANs.
2 In the Content panel, select the VLAN.
3 Click Properties.
4 Click the VLAN Member Details tab.
5 To add a static multicast receiver port, select the Forward Multicast IP
Out checkbox for each port you want to add.
By default, ports are not selected. To remove a static multicast receiver
port, clear the checkbox.
6 To add a multicast router port, select the Multicast Router Present
checkbox for each port you want to add.
By default, ports are not selected. To remove a static multicast receiver
port, clear the checkbox.
7 Click OK.
Viewing and Configuring VLANs 225