Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!rochester!rutgers!ames!ucbcad!ucbvax!NUHUB.ACS.NORTHEASTERN.EDU!JOHNSON From: JOHNSON@NUHUB.ACS.NORTHEASTERN.EDU ("I am only an egg.") Newsgroups: comp.protocols.tcp-ip Subject: ethernet interface perversity Message-ID: <8708050046.AA07011@ucbvax.Berkeley.EDU> Date: Tue, 4-Aug-87 17:03:00 EDT Article-I.D.: ucbvax.8708050046.AA07011 Posted: Tue Aug 4 17:03:00 1987 Date-Received: Thu, 6-Aug-87 07:02:28 EDT Sender: daemon@ucbvax.BERKELEY.EDU Distribution: world Organization: The ARPA Internet Lines: 55 Hold it a minute. I have received many responses from my query about network numbers on an ethernet. Thank you for all the positive help for those who gave it but . . . I NEVER intended to complain or panic about IP. I was in search of verification of something and perhaps I phrased it poorly. And yes I know that one ethernet wire can have large numbers of internet addresses floating around on it. We did some experimentation with our various ethernet interfaces and discovered that something which was hinted at in many of the responses seems to be true. The ethernet interfaces we have will each respond to only one internet number at a time. I talked to Micom for example and they even said as much for their np100 board. *FLAME ON* It seems very dumb that I need at least one gateway node on one ethernet wire so that nodes on that wire can all talk to each other when some of the nodes run with different internet numbers. Although my problem is really an administrative one (I don't run the whole network here, I just get dumped on when it doesn't work), I don't see why I should be having a problem at all. I read ARP, rfc 826, and it talks about an address translation table. Note the use of the word TABLE. In this age of micro-processors it seems more than feasible to put some real table driven ARP intelligence out there so that interface boards can RESPOND TO MORE THAN ONE BLOODY ADDRESS. I suppose someone is going to ask how big the table should be. I don't know. Memory is cheap. It could easily be big enough to handle 16 or 32 network numbers. It could even be content addressable and thus FAST. Allowing for 16 or 32 network numbers (or more) should reduce the frequency of ether_type$ADDRESS_RESOLUTION packets to small for most cases. *FLAME OFF* I'm just upset with the vendors for giving me ulcers again. So what else is new :-(. USnail: Chris Johnson Academic Computer Services Northeastern University 39RI 360 Huntington Ave. Boston, MA. U.S.A. 02115 AT&T: (617) 437-2335 CSNET: johnson@nuhub.acs.northeastern.edu ARPANET: johnson%nuhub.acs.northeastern.edu@relay.cs.net BITNET: johnson%nuhub.acs.northeastern.edu@csnet-relay (Always vote. There may not be anything you want to vote for, but there might be something you want to vote against.)