I wonder if you haven't told the full story here. Why would you need ping?
Or are you writing that any machine doesn't work at all on the new switch? If so, the switch may have failed or indeed you don't have CAT5 (category 5) wiring.
We have 15-25 computers running in our orgnisation. One computer is Win 2000 Server and others are Win2k Professional connected via 8 port hub, cat 5 cable (D-LINK made), RJ45 Jacks (Wall mounting). Everything was fine till we changed hub to 24 port switch. Now no computer is able to ping each other. It gives request time out error. Then somebody told to decrease the lan card speed from 100mb full duplex to 10mb half duplex (He gave the reason that electrical wires may be running near lan wires, which is true as at some point they are running close to each other). All cables are running underground and in the walls. For testing, we laid a calbe outside the walls and it worked on 100mbs full duplex speed but it still gave timeout error after 50-100 successfull pings. Sombody also told us that our calbe is not 100mbs comptable.
Please let us know, what is the actual cause of this problem. Everything works fine on hub but speed is very slow.
Thanks in advance