Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!wuarchive!zaphod.mps.ohio-state.edu!samsung!noose.ecn.purdue.edu!mentor.cc.purdue.edu!dls From: dls@mentor.cc.purdue.edu (David L Stevens) Newsgroups: comp.protocols.tcp-ip Subject: Re: IP numbers that end in 0 ... Message-ID: <13391@mentor.cc.purdue.edu> Date: 28 Aug 90 15:53:45 GMT References: Reply-To: dls@mentor.cc.purdue.edu (David L Stevens) Organization: PUCC UNIX Group Lines: 15 I've seen two articles now that suggest that it is legitimate to filter directed broadcasts if the gateway thought they were. Note that it is wrong to do so, at least for destinations, in the first place. It is perfectly legitimate for me to address a broadcast packet to a remote network. I could see where a gateway might arguably drop packets whose source address is a broadcast address, but that's a little more intrusive than I'd want a gateway to be. The host can and should take responsibility for that sort of checking. A gateway should just do ttl, checksum and routing and leave everything else alone. So even if these routers did have the right sense of what a broadcast packet on a remote network is, which they can't have, they should not be discarding those packets. -- +-DLS (dls@mentor.cc.purdue.edu)