keith@mva.cs.liv.ac.uk (10/03/88)
We have quite a major problem in getting HP 9000/300 equipment to talk TCP/IP with a microVAX II running VMS V4.7 and CMU IP/TCP V6.3 over ethernet. Basically, FTP and TELNET connections don't seem to last very long - the microVAX aborts with TCP Receive errors. Worse still, using PING on the HP system to ping to the vax with packet sizes in excess of 800 (or so) characters causes the IP_ACP on the microVAX to completely abort with an access violation. We have absolutely no problem communicating with an HLH Orion as long as IP trailers are turned off and the Orion communicates quite happily with the HP system. As the the HP system doesn't appear to support IP trailers, we assume that there is a resource problem. Should something in INTERNET.CONFIG be tweaked? The documentation isn't very helpful. Any assistance would be very welcome... Keith Keith Halewood Janet: KEITH@UK.AC.LIV.CS.MVA Internet: KEITH%MVA.CS.LIV.AC.UK@CUNYVM.CUNY.EDU UUCP(Ugh): {wherever}!mcvax!ukc!mupsy!liv-cs!keith
marius@rhi.hi.is (Marius Olafsson) (10/07/88)
From article <2969@mva.cs.liv.ac.uk>, by keith@mva.cs.liv.ac.uk: > We have quite a major problem in getting HP 9000/300 equipment to talk > TCP/IP with a microVAX II running VMS V4.7 and CMU IP/TCP V6.3 over > ethernet. > > Basically, FTP and TELNET connections don't seem to last very long - the > microVAX aborts with TCP Receive errors. .. The CMU-TEK implementation periodically sends so-called "inactivity probes" over its connections to ascertain that the connection is still alive. It is our experience that HP-UX always aborts the connection upon receiving these probes. To quote from the CMU-TEK code: ............ Currently, we will send an unacceptable segment with SYN and ACK on with a bogus sequence number. According to the TCP spec, such a segment should either generate an ACK with the correct sequence numbers or should generate an RST if the connection does not exist. The problem is that HP-UX always generates RST. It would be nice if someone from HP could comment wether this is a case of different interpretation of the TCP spec or a bug in HP-UX. Anyway, there does not seem to be a way to turn this off in CMU-TEK, and the only way we had to make the HP-UX/CMU-TEK combination behave was to patch CMU-TEK to eliminate these "inactivity probes". Mail for details if anyone is insterested. Our config (11/780 VMS 4.7+CMU-TEK-6.3 HP-9000/840 HP-UX 1.2) -- Marius Olafsson Internet: marius@rhi.hi.is University of Iceland Non-MX: marius%rhi.hi.is@uunet.uu.net UUCP: {mcvax,enea,uunet}!hafro!rhi!marius