Multicast
Multicast Overview
This chapter shows you how to configure various multicast features.
Traditionally, IP packets are transmitted in one of either two ways – Unicast (one sender to one recipient) or Broadcast (one sender to everybody on the network). Multicast delivers IP packets to just a group of hosts on the network.
IGMP (Internet Group Management Protocol) is a network-layer protocol used to establish membership in a multicast group – it is not used to carry user data. Refer to RFC 1112, RFC 2236 and RFC 3376 for information on IGMP versions 1, 2 and 3 respectively.
What You Need to Know
IGMP Proxy
Internet Group Management Protocol (IGMP) proxy is used for multicast routing. IGMP proxy enables the Zyxel Device to issue IGMP host messages on behalf of hosts that the Zyxel Device discovered on its IGMP-enabled interfaces. The Zyxel Device acts as a proxy for its hosts. Refer to the following figure.
• DS: Downstream traffic
• US: Upstream traffic
• R: Router
• MS: Multicast Server
• Enable IGMP Upstream (US) on the Zyxel Device interface that connects to a router (R) running IGMP that is closer to the multicast server (MS).
• Enable IGMP Downstream on the Zyxel Device interface which connects to the multicast hosts.
The Multicast Screen
Click Network > Multicast to open the Multicast screen. Use this screen to:
• Turn IGMP Proxy off or on
• Configure multicast traffic
• View multicast traffic status
The following table describes the labels in this screen.
Label | Description |
|---|---|
IGMP Proxy | |
Enable | Turn on the IGMP Proxy to enable the Zyxel Device to route multicast traffic. |
Multicast Address Reception | Allow all Multicast Addresses: Select this to have the Zyxel Device send all multicast traffic to all the IGMP hosts.  If too much multicast traffic congests your network, you may choose the following option.Allow the Following Multicast Addresses: Select this to have the Zyxel Device send multicast traffic only to the selected IGMP hosts. Click the edit icon to select existing IP address objects or create new ones. |
Upstream Interface | Select the interface that connects to a router (host) running IGMP and closer to the multicast server. You can assign Ethernet, VLAN, Bridge, or LAG interfaces as IGMP Proxy upstream interfaces. |
Downstream Interface | Select the interface that connects to the multicast hosts. You can assign Ethernet, VLAN, Bridge, or LAG interfaces as IGMP Proxy downstream interfaces. |
Multicast Status | This shows information about which multicast groups are currently active and how the multicast traffic pass through the Zyxel Device. |
Group | This shows the multicast group IP address the multicast traffic belongs to. The multicast traffic in this group is forwarded to the downstream interfaces. |
Source IP | This shows the IP address of the multicast server. |
Upstream Interface | This shows the interfaces on which the Zyxel Device receives multicast traffic. |
Downstream Interface | This shows the interfaces to which the Zyxel Device forwards multicast traffic. |
Apply | Click Apply to save your changes back to the Zyxel Device. |
Cancel | Click Cancel to return the screen to its last-saved settings. |