I'm new to Experts-Exchange and this is my first (though probably not last) question! I'm really hoping that someone can help me out.
First off a little background - I'm a scuba diving instructor working in Bali and also happen to be the local computer "expert" (not so much from my expertise but since I have a degree in Computer Science that puts me light-years ahead of anyone else around here).
I've setup the office network here to be a little bit more efficient and secure than what it was when I arrived. To briefly describe the setup I have:
• Linksys Wireless-G ADSL Home Gateway (WAG200G) that acts as the office internet connection.
• To this I have a server connected running Windows Server 2008 with DNS, DHCP, Active Directory installed and running.
• Also to the router I have a switch connected (3COM Office Connect Fast Ethernet Switch 16 (3C16792C)).
• To the switch I have all the office computers connected (6 in total). I also have another switch connected to it (in another building) which has our CCTV recorder connected and then yet another switch which serves two additional computers in a classroom. Both of those switches are 3COM 8 ports (3CFSU08).
Now to the problem:
I tidied up the cables behind the 16 port switch today (it was a horrific mess of cables) and in the process disconnected the cables, sorted them out then reconnected them (admittedly, not in the same sockets they were originally in). Once everything was reconnected I quickly checked all of the machines to see if the network connectivity was working and it was on all expect two.
These two machines are in the main office so connected directly to the 16port switch. The issue they are having is the "Limited or No Connectivity" due to an IP address not being assigned. Attempting to repair (or ipconfig /release and then /renew) ends up with Windows telling me that the DHCP server cannot be reached. Every other machine on the network is getting IP addresses fine and is working normally.
Now the strange thing is that if I plug those two machines directly into the Linksys router, then connectivity is restored. It's only if they're plugged into the 16 port switch that they lose it. I've tried everything I can think of including: rebooting the switch, changing ports on the switch, trying other computers on the ports of those machines, trying new cables, reinstalling network card drivers, running network card diagnostics, rebooting the server etc and nothing helps.
So I'm wondering if anyone has any ideas why the network works fine if I plug the computers directly into the router and not if I use the switch (keeping in mind that there are 4 other machines directly connected to the same switch which work, the CCTV works as do the two machines off in the classroom)?
I'll be happy to provide any additional information if you need it.