The office where I do I.T. had a strange issue today. We had 2 people move positions. They took their computers and shore tel lan phones with them.
This is how the devices connect: The phone is hard wired from the wall (phone has in and out 2 ports), the computer is hard wired from the phone to the computer. The shore tel phones have static IP which are excluded from the dhcp server range and routed to the shore tel server. The computers are set to use DHCP. We have 3 24port poe switches (all connected together from bottom to middle then middle to top)
The phones were able to connect and worked after the move on the new lan connections, however on both computers there was no connection (got an ip but no connection to the internet). I tried linux on both machines thinking maybe software problem, still no connection.
Here is the strange part: A different laptop plugged into the back of either phone would instantly connect and have internet.
I logged into the 3 24port poe switches no issue could be found, in the DHCP server I tried kicking both computers from their ip addresses so they could reconnect.
I ended up re-routing their original lan floor spots to the switches so it was as if they had never moved. Both computers then connected normally.
Maybe a key to the puzzle, one computer (A) was originally in the bottom switch, the other ( was in the middle switch. When moved to their new positions (A) was now in the middle switch and ( was in the bottom.
Also it seemed on both computers they would not renew to a different lease, for example (A) was on 192.xxx.xx.122 and after release and renew would grab the same lease even though many were open. No device was grabbing 122 before that computer could. I am not sure how but it seems the computer is using a static ip, maybe the shore tel phone is assigning this? I saw no reason for this to be happening.
I did not set this network up and currently I am at a loss. Any ideas?
My thought is that it is something to do with the shore tel phones taking the mac address of the computer and somehow forcing static ip, the shore tel phone server does make use of the phones mac address. Still I would think kicking the computer from the DHCP server and leaving 122 open, it should reconnect and have internet.
EDIT: One other thing, in ipconfig on both computers (when they were not connecting to internet) I could see the correct gateway but could not ping it or would have 100% loss.
Anyway for now the system is working, I now fear any big moves...
Edited by zingo156, 07 February 2014 - 12:48 PM.