On Wed, May 05, 2004 at 11:18:41AM -0700, DaveC wrote: > I'm trying to understand the difference between these two. An > off-the-cuff poll seems to result in this semi-consensus: Both a router and bridge are designed to glue to networks together.
The bridge knows NOTHING about IP addresses (layer 3) and only deals with the MAC addresses (layer 2). Therefore the bridge inspects the packet destinations by MAC (hardware) address, and passes only packets that have destinations across the bridge. The typical wireless bridge, when connected to an access point, will only pass one MAC address across the bridge. Therefore, you cannot use a simple wireless bridges to glue two networks, consisting of multiple machines together. This is the common arrangement for a point to multi-point bridge. A transparent bridge is normally a point to point device, that will pass multiple MAC addresses and therefore can glue two networks of multiple machines together. The decision as to which packets go across is strictly at the MAC (hardware) level. No IP addresses are involved (except perhaps for managing the bridge). A router does much the same except at the IP address level. The decision as to whether to pass packets is made by inspecting the IP address header and determining if the destination IP address is on the other side of the router. The degree of complexity by which this is done is limited only by the imagination of the router firmware authors. For example, a router will "sniff" the packets to determine the type of service to make decisions for ftp, H.323, some games, and other poorly written protocols. In the case of a wireless router, this is somewhat of a misnomer. The box is really a wireless bridge connected to one port of a switch, which connects to a router. Traffic on the wireless port is effectively point to multi-point bridgeing, not routeing, as it only acts as a bridged extension cable for switched port. -- # Jeff Liebermann Liebermann Design 150 Felker St #D Santa Cruz CA 95060 # 831.336.2558 voice 831.421.6491 digital_pager AE6KS # [EMAIL PROTECTED] http://www.LearnByDestroying.com _______________________________________________ BAWUG's general wireless chat mailing list [unsubscribe] http://lists.bawug.org/mailman/listinfo/wireless
