The value of tmnxSubIgmpPlcyHostMaxSources specifies the maximum number
of sources for which IGMP can have local receiver information based on
received IGMP reports for this host. When this configuration is changed
dynamically to a value lower than currently accepted number of sources,
the sources that are already accepted are not deleted. Only new sources
will not be allowed. When this object has a value of 0, there is no
limit to the number of sources.