Westermo RedFox Series - Manual (Page 386)

Westermo OS Management Guide
Version 4.17.0-0
18.1.4 Low Bandwidth Networks
In low-bandwidth topologies, like FRNT over an SHDSL ring, you typically cannot
afford wasting bandwidth on unwanted traffic. With the IGMP Proxy Mode and
Fast Leave settings for IGMP snooping this can be avoided.
In the standard auto mode of IGMP all unknown multicast must be forwarded to
the elected querier. But if there is no elected querier, or if all switches instead
have proxy mode enabled, unknown multicast will be stopped before entering
the low-bandwidth ring.
Only when a subscriber appears will the traffic be classified as known and for-
warded on the ring to the receiver. By also enabling Fast Leave, on the access
port towards the receiver, the multicast overhead can be kept to a near minimum.
386 ➞ 2015 Westermo Teleindustri AB