64 Bridging
Bridge Filtering
Identifying Address Links for MAC Addressing
Why it is Important Identifying the address links is an important step in configuring MAC Address
filtering.
A Source Address link allows a device on the LAN to send frames. ADestination
Address link allows a device on the LAN to receive frames.
The Incoming Source Address link provides a path for a frame to go from the Tok en
Ring to the bridge. The Outgoing Source Address link provides a path for a frame to
go from the bridge to the WAN.
The Incoming Destination Address link provides a path for a frame to go from the
WAN to the bridge. The Outgoing Destination Address link provides a path for a
frame to go from the bridge to the LAN.
Example of
Address Links Figure 33 shows that link 5 serves as both the Outgoing Source Address link and the
Incoming Destination Address link. In this example, Outgoing Source Address link 5
allows the File Server with MAC Address 10:00:5A:00:00:40 (the source) to send
frames to the WAN via link 5. Incoming Destination Address link 5 allo w s the File
Server with MAC Address 10:00:5A:00:00:40 (the destination) to receive frames
from the WAN via link 5.

Figure 33. Example of Address Links

Token
Ring 2
LAN
File Server
MAC Address 10:00:5A:00:00:40
Outgoing Source Address Link (MAC Address 10:00:5A:00:00:40)
Incoming Destination Address Link (MAC Address 10:00:5A:00:00:40)
5
6
1
Node 100
Bridge
Incoming Source Address Link (MAC Address 10:00:5A:00:00:40)
Outgoing Destination Address Link (MAC Address 10:00:5A:00:00:40)
W
AN