Path: utzoo!attcan!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!fiamass.ie!sean From: sean@fiamass.ie (Sean Mc grath) Newsgroups: comp.protocols.tcp-ip Subject: TCPIP ping problem Message-ID: <9012141526.AA18800@fiamass.ie> Date: 14 Dec 90 15:26:28 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 49 Apologies for being a bit short in information with my last posting. here is a more complete description of my problem. Hardware :- Two Nec 386 PC machines. 1 with wd8003 ethernet board. 1 with 3c503 ethernet board. Software :- PC/TCP from FTP software version 2.05 The machines are connected over thin ethernet forming a bare two machine network. Configuration is as follows :- Machine A Machine B ========== ========== IP address : 192.9.200.2 IP address : 192.9.200.7 Ethernet : 2:60:8c:d:a1:a3 Ethernet : 0:0:c0:d3:55:18 3c503 ethernet board. WD8003 ethernet board. local file used on either end as hosttable. (Files are identical) time ordering of events is as follows :- Machine A Machine B Result ========== ========== ======= reboot. Reboot. inet arp cache empty inet arp cache empty ping A ARP fails. Host unreachable. inet arp cache empty inet arp cache empty ping B Succeeds. inet arp Entry for B in cache. inet arp Entry for A in cache. It seems to me that machine A must be caching the ethernet address of B after B does "ping A" otherwise its own ping would fail. If so, why do the caches look empty? Any help would be gratefully received. Sean Mc Grath (sean@fiamass.ie) Fiamass Ltd. 12 Clarinda Park North Dun Loaghaire Co. Dublin Ireland.