Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site mit-eddie.MIT.EDU Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!mar From: mar@mit-eddie.MIT.EDU (Mark Rosenstein) Newsgroups: net.micro,net.lan Subject: Re: License violation detection Message-ID: <1390@mit-eddie.MIT.EDU> Date: Tue, 25-Mar-86 15:07:42 EST Article-I.D.: mit-eddi.1390 Posted: Tue Mar 25 15:07:42 1986 Date-Received: Wed, 26-Mar-86 07:06:43 EST References: <141@suneast.uucp> <20520@styx.UUCP> Reply-To: mar@mit-eddie.UUCP (Mark Rosenstein) Organization: MIT, EE/CS Computer Facilities, Cambridge, MA Lines: 12 Keywords: UDP ICMP discard Xref: watmath net.micro:14125 net.lan:1379 Summary: not everyone implements UDP discard In article <20520@styx.UUCP> fair@styx.UUCP (Erik E. Fair) writes: >So in effect, everyone implements UDP discard (because of the way that >UDP is specified) if they implement UDP at all. Not true! If they do a compelete implementation of the IP protocol suite, then they will send an ICMP destination port unreachable message back for each received UDP packet without a listener on that port. Granted hosts should not send ICMP messages in response to broadcast packets, but many do. This could cause a flood of packets if one broadcasts UDP packets on a network with many hosts which do this. -Mark