IGMP Proxy
IGMP proxy sends IGMP host messages on behalf of a connected client. The configuration must define one, and only one upstream interface, and one or more downstream interfaces.
Configuration
upstream: The upstream network interface is the outgoing interface which is responsible for communicating to available multicast data sources. There can only be one upstream interface.
downstream: Downstream network interfaces are the distribution interfaces to the destination networks, where multicast clients can join groups and receive multicast data. One or more downstream interfaces must be configured.
Defines alternate sources for multicasting and IGMP data. The network address must be on the following format ‘a.b.c.d/n’. By default, the router will accept data from sources on the same network as configured on an interface. If the multicast source lies on a remote network, one must define from where traffic should be accepted.
This is especially useful for the upstream interface, since the source for multicast traffic is often from a remote location.
This option can be supplied multiple times.
Disables quickleave mode. In this mode the daemon will not send a Leave IGMP message upstream as soon as it receives a Leave message for any downstream interface. The daemon will not ask for Membership reports on the downstream interfaces, and if a report is received the group is not joined again the upstream.
If it’s vital that the daemon should act exactly like a real multicast client on the upstream interface, this function should be enabled.
Enabling this function increases the risk of bandwidth saturation.
Example
Interface eth1 LAN is behind NAT. In order to subscribe 10.0.0.0/23 subnet multicast which is in eth0 WAN we need to configure igmp-proxy.
set protocols igmp-proxy interface eth0 role upstream
set protocols igmp-proxy interface eth0 alt-subnet 10.0.0.0/23
set protocols igmp-proxy interface eth1 role downstream