Motorola 2200 ユーザーズマニュアル

ページ / 368
Administrator’s Handbook
104
Link: 
Ethernet Bridge
The Motorola Netopia® Gateway can be used as a bridge, rather than a router. A bridge is a device that 
joins two networks. As an Internet access device, a bridge connects the home computer directly to the ser-
vice provider’s network equipment with no inter vening routing functionality, such as Network Address Trans-
lation. Your home computer becomes just another address on the ser vice provider’s network. In a DSL 
connection, the bridge ser ves simply to convey the digital data information back and for th over your tele-
phone lines in a form that keeps it separate from your voice telephone signals.
If your ser vice provider’s network is set up to provide your Internet connectivity via bridge mode, you can set 
your Motorola Netopia® Gateway to be compatible.
Bridges let you join two networks, so that they appear to be par t of the same physical network. As a bridge 
for protocols other than TCP/IP, your Gateway keeps track of as many as 512 MAC (Media Access Control) 
addresses, each of which uniquely identifies an individual host on a network. Your Gateway uses this bridg-
ing table to identify which hosts are accessible through which of its network inter faces. The bridging table 
contains the MAC address of each packet it sees, along with the inter face over which it received the 
packet. Over time, the Gateway learns which hosts are available through its WAN por t and/or its LAN por t.
When configured in Bridge Mode, the Motorola Netopia® will act as a pass-through device and allow the 
workstations on your LAN to have public addresses directly on the internet. 
☛  
NOTE:
In this mode the Motorola Netopia® is providing NO firewall protection as is afforded by NAT. 
Also, only the workstations that have a public address can access the internet. This can be 
useful if you have multiple static public IPs on the LAN.
Bridging per WAN is suppor ted in conjunction with VLANs – individual WANs can be bridged to the LAN only 
if the WANs are par t of a VLAN. (See 
 for more information.) The capability to bridge 
individual VLANs is suppor ted only if the underlying encapsulation is RFC1483-Bridged (ether-llc).