Yes, IPV4 network, all servers have a fixed IP (won't work outside via the WAN without them)
I even removed a switch and a LynkSys (DD-WRT flashed) router and problem still remained (see diagram above in msg #44315) between Client computer #1 and SDR-iq Server #2 & #3. Still the same behavior, but if I connect to any of my SDRplays, (SDRPlay #2 is not shown on the above diagram since it was removed for testing) no issues what so ever going through the same series of switches at 1 MHz bandwidth.
I do have long runs of CAT6 from house to barn ~250' and from barn to repeater shed ~150', but as previously mentioned some SDR's work fine and some not so good via select clients. I spend most of my computer time using my XYL's 10 yr old Laptop, the one running the AirspyHF+ server. That old machine accesses all my SDR's just fine, go figure!
Will try the NETSTAT diagnostics this AM....
73 Kriss KA1GJU