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HP OpenVMS Systemsask the wizard |
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The Question is: A previously independent network (with 16 nodes and unknown protocols) was brought onto our network. (I know, I know, stop laughing now...) This black box network, once connected to our large multi-protocol network, caused an existing and previously operational LAT/VAX/terminal server-type network to experience intermittent operation (all terminal server/LAT connex. would get terminated with "illegal circuit" indications at the terminals every 1 to 3 minutes). The terminal servers are a combination of Xyplex and Cabletron ETSMIM cards. A NGC protocol sniffer shows the VAX machine issuing a disconnect because of an illegal format, with a VAX source circuit id of 0000. Note that people using TCP/IP to connect to the same resource experience no problems (using "Reflections"? software). What might be the various reason(s)/cause(s) for LAT to terminate ALL the terminal sessions? (note that the users can connect right back to the vax again, but then they get kicked off within minutes). I read as much as I can find about the lat protocol, but I haven't found "troubleshooting" type of info, just "theory of operation" type info. Thanks!! The Answer is : TCP/IP is an entirely separate protocol from LAT, only those problems in common network hardware, with bridges, or resulting from network congestion will tend to affect both protocols. This question is well beyond the purvue of the OpenVMS Wizard, and this will require the assistance of the customer support center to resolve. It would appear that there are network problems or potentially problems with the LAT implementation on the Xyplex or Cabletron servers, or there are problems induced by other hardware present on the network.
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