Forward Or Filter; Mac Address Table Configuration Task List - Planet Networking & Communication WGSW-50040 Configuration Manual

11.1.2 Forward or Filter

The switch will forward or filter received data frames according to the MAC table. Take the above figure as an
example, assuming switch have learnt the MAC address of PC1 and PC3, and the user manually configured
the mapping relationship for PC2 and PC4 to ports. The MAC table of switch will be:
MAC Address
00-01-11-11-11-11
00-01-22-22-22-22
00-01-33-33-33-33
00-01-44-44-44-44
1. Forward data according to the MAC table
If PC1 sends a message to PC3, the switch will forward the data received on port 1/5 from port1/12.
2. Filter data according to the MAC table
If PC1 sends a message to PC2, the switch, on checking the MAC table, will find PC2 and PC1 are in the
same physical segment and filter the message (i.e. drop this message).
Three types of frames can be forwarded by the switch:
 Broadcast frame
 Multicast frame
 Unicast frame
The following describes how the switch deals with all the three types of frames:

Broadcast frame: The switch can segregate collision domains but not broadcast domains. If no
VLAN is set, all devices connected to the switch are in the same broadcast domain. When the
switch receives a broadcast frame, it forwards the frame in all ports. When VLANs are configured in
the switch, the MAC table will be adapted accordingly to add VLAN information. In this case, the
switch will not forward the received broadcast frames in all ports, but forward the frames in all ports
in the same VLAN.

Multicast frame: When IGMP Snooping function is not enabled, multicast frames are processed in
the same way as broadcast frames; when IGMP Snooping is enabled, the switch will only forward
the multicast frames to the ports belonging to the very multicast group..

Unicast frame: When no VLAN is configured, if the destination MAC addresses are in the switch
MAC table, the switch will directly forward the frames to the associated ports; when the destination
MAC address in a unicast frame is not found in the MAC table, the switch will broadcast the unicast
frame. When VLANs are configured, the switch will forward unicast frame within the same VLAN. If
the destination MAC address is found in the MAC table but belonging to different VLANs, the switch
can only broadcast the unicast frame in the VLAN it belongs to.

11.2 Mac Address Table Configuration Task List

1. Configure the MAC address aging-time
2. Configure static MAC forwarding or filter entry
Port number
1/5
1/5
1/12
1/12
11-3
Entry added by
Dynamic learning
Static configuration
Dynamic learning
Static configuration