Upvel UP-308FEW User Manual page 47

UP-308FEW / UP-316FEW
IGMP Snooping V1 & V2
By default, a switch will flood multicast traffic to all ports in a broadcast domain. Multicast may
cause unnecessary load on host devices by requiring them to process packets they have not
solicited. The IGMP snooping feature allows the switch to listen in on the IGMP
communications between hosts and routers. By listening (also known as snooping) to these
communications, the switch maintains a map of which ports (clients) need which multicast
stream (source). Multicast that is not solicited by certain clients (or IGMP group) will be
filtered.
VLAN Uplink Setting
This switch does not implement an Independent VLAN (IVL) MAC address table, it utilizes
VLAN uplink to emulate the function of IVL. An independent VLAN MAC address table is
based on both the source MAC address and the VLAN. In some applications, if the switch
cannot build the separate MAC address table for different VLANs, there will be a conflict of
MAC address table. To solve this problem, the switch controller utilizes the VLAN Uplink port
to emulate the usage of Independent VLAN MAC Address Table.
VLAN Uplink function allows different VLANs to use individual uplink port to forward packets.
In a normal application, only one uplink port can be selected in a switch.
If VLAN Uplink function is enabled and the destination port of a unicast packet is located at
the next VLAN, this packet will be forwarded to the uplink port. Choose the Uplink Port X for
the port ID. The Uplink X will be the uplink port of its VLAN.
Note. There is a functional conflict between VLAN Striding and VLAN Uplink. So if both
VLAN Striding and VLAN Uplink are enabled simultaneously, the switch selects VLAN
Striding and ignores the VLAN Uplink setting.
User Manual 47