An IGMP proxy is typically used for Internet connections with multicast IPTV. Clients or IPTV set top boxes (STBs) on the local network send IGMP messages to receive a specific TV channel. To this end, they join certain multicast groups and later leave them again. The router and/or IGMP proxy receives the IGMP messages and forwards them to the provider network and filters the groups, if required. The IGMP proxy works for the local network with its clients.
An IGMP proxy can also be used in simple multicast routing scenarios, for example via VPN, without having to use PIM. The configuration of the IGMP proxy creates a static (tree) structure without alternative paths, redundancy or loop prevention. IGMP proxies can be "cascaded" by connecting multiple routers in series.
The IGMP proxy doesn't support BiDirectional Multicast. Therefore the interfaces must not be entered crosswise in the IGMP proxy.
In LANconfig you configure the IGMP proxy under via IGMP proxy.
- Downstream interface
- Interface name used by IGMP clients to join groups and receive IGMP messages from the proxy. Possible values are IPv4 networks, e.g. INTRANET, IPv4 (WAN) remotes. Also allowed are wildcard entries with * for RAS interfaces, e.g. "VPN*". For provider-based IPTV scenarios, the local network, e.g. INTRANET, must be configured here.
- Upstream interface
- Interface name used by the IGMP proxy to send messages on behalf of clients. The source of the multicast messages must be reached via this interface. Possible values are IPv4 networks, e.g. INTRANET and IPv4 (WAN) remotes. For provider-based IPTV scenarios, the WAN remote site, e.g. INTERNET, must be configured here.
- Group filter
- Name of the group filter that is to apply to this proxy. References the table IPv4 filter lists under . By default, the filter entry is blank or points to the filter list "ANY", which allows all multicast groups. The group filter can be used to restrict the multicast groups available for clients.
