> During the period when the failing FTP client PC can't ping the > server, other PCs can ping it without trouble. Then it sounds like a network problem. How much stuff (firewalls, routers, ...) lies between these systems? Are these "other PCs" on the same network segment (real, virtual) as the failing one? > [...] 'log files' [...] SYS$SYSDEVICE:[TCPIP$FTP]TCPIP$FTP_RUN.LOG But if the problem is external to the VMS system, then that probably won't reveal much, either. > TCPIP version is v5.6 ECO 2. Machine is an rx2660. With hobbyist patch access being what it is these days, I don't know if that's current, but it may not matter. Hmmm. Around here: IT $ tcpip show version HP TCP/IP Services for OpenVMS Industry Standard 64 Version V5.6 - ECO 5 on an HP zx2000 (1.50GHz/6.0MB) running OpenVMS V8.3-1H1 So ECO 2 would seem to be stale. But probably not relevant. So far as I know, TCPIP has no lock-out mechanism triggered by excessive activity. (If it did, then it might be useful when some hijacked Windows system runs an SSH break-in attack on my Alpha.)