APC PDU 8886 WITH NMC3 NETWORK PROBLEM

[mosheshiper]

HELLO

We have new pdus AP8886 with NMC3. When we connect its network port to cisco switch the link stay down and the light on the network port and on the switch are off. When i connect the PDU network direct to my pc computer the pc connect (web) to the PDU and all lights on PDU network card are on. I want to say that the  new PDU is connected to switch port that now AP8886 with NMC 2 connect to it and work but when we connect the NMC 3 it does not work - there is no connect even on layer 1-2 the are off. We check the port switch and the PDU port By connect it to pc and to another PDU network port and it work but not when we connect it to the switch. I also upgrade the firmware of the PDU 

WHY??? what can i chek ?

thanks

[mosheshiper · Accepted solution]

Problem solved. I upgrade the firmware and from serial port i change the port speed to auto and reboot the network card .