DHCP problem

I am sorry to widespread this problem, I don't know where exactly to post this DHCP problem.

I had very starange DHCP problem. If I connect corporate LAN connection to my PC, it gets IP addrerss from DHCP server. We had third party switch, its Uplink is connected to LAN, one of the downlink is connected to PC, the PC never gets its IP address, at the end it fails because DHCP server unreachable. If I connect a laptop with DHCP server on Uplink side, the PC gets IP addr immediately. But if I replace laptop by LAN connection, the PC never gets IP addr. PC keeps sending DHCP discovery packets, it never gets reply from DHCP at all. I had etheral on PC, I can see lot of network packets also. But this DHCP discover packet never gets replied. What do you think?. Thanks in advance.

Well without knowing more about the network, I would wonder what is on the other side of the UPLINK cable. Not knowing anything about the company there are any number of isses possible. One could be the percise use of VLAN's on the LAN. If configured by MAC then your laptop would not be assigned to a VLAN.

Second, are any other computers on that switch getting a DHCP reply?

Third, try plugging right into the UPLINK cable for the upstream side of the LAN into your laptop. Are you getting a response?

Can you ping the DHCP server from the switch?

Drop a little more info and maybe someone can help you further.