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Bridging with a Cisco 700 Series Router
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Bridging with a Cisco 700 Series Router
This section describes how to bridge a Cisco 700 series router over an ISDN line to another router. Bridging is used in cases where you do not need a lot of filtering to manage the network. Basically, you are relying on the nodes on the LAN side of the router to determine if a packet should be accepted or dropped. (If you turn routing on, you can filter the packets on the WAN side, reducing your traffic on the LAN side.)
Note Bridging over an ISDN line is not an efficient use of ISDN bandwidth. Routing over the ISDN line helps optimize ISDN bandwidth by reducing traffic to the WAN.
Figure 3-1 illustrates an example of a remote Cisco 700 series router bridging to a router called central at a central site.
Figure 3-1 Bridging Example
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H5860
You are going to establish a basic connection with another router, relying primarily on the defaults. In this example configuration, a simple
By default, the Cisco 700 series router automatically “learns” the MAC addresses that exist locally and remotely across the WAN. The router stores the MAC addresses in a MAC address table, so it knows if the unicast packets should remain on the LAN or forwarded