Path: utzoo!utgpu!water!watmath!clyde!rutgers!ames!ucbcad!ucbvax!VENERA.ISI.EDU!braden From: braden@VENERA.ISI.EDU Newsgroups: comp.protocols.tcp-ip Subject: Re: Routers vs. Bridges Message-ID: <8712101742.AA23362@braden.isi.edu> Date: 10 Dec 87 17:42:18 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The ARPA Internet Lines: 13 Here is one way you might decide if a given box is a bridge or an IP gateway (aka router): see if it forwards a local network broadcast packet. A bridge "must" forward broadcasts, while a gateway "must never" forward one. Another test: see if the IP network number changes when the packet is forwarded. A bridge must not change anything in the IP header, while a gateway "must" change the IP destination address. These two tests give some clues about the advantages of gateways over bridges. Bob Braden