User manual

DG-BG4300N User Manual
IP hosts use Internet Group Management Protocol (IGMP) to report their multicast group
memberships to neighboring routers. Similarly, multicast routers use IGMP to discover which of their
hosts belong to multicast groups. This device supports IGMP proxy that handles IGMP messages.
When enabled, this device acts as a proxy for a LAN host making requests to join and leave multicast
groups, or a multicast router sending multicast packets to multicast group on the WAN side.
When a host wishes to join a multicast group, it sends IGMP REPORT message to the device’s IGMP
downstream interface. The proxy sets up a multicast route for the interface and host requesting the
video content. It then forwards the Join to the upstream multicast router. The multicast IP traffic will
then be forwarded to the requesting host. On a leave, the proxy removes the route and then forwards
the leave to the upstream multicast router.
7.1.1 IGMP Proxy Configuration
The IGMP Proxy page allows you to enable multicast on WAN and LAN interfaces. The LAN
interface is always served as downstream IGMP proxy, and you can configure one of the available
WAN interfaces as the upstream IGMP proxy.
Upstream: The interfaces that IGMP requests from hosts are sent to the multicast router.