How to read optical module information on a network card on Linux systems

      Optical modules can be used in addition to switches, routers and other independent devices, can also work in the network adapter, which is what we usually call the network card. We know that the optical module applied to the switch, according to the brand of the switch, the terminal using the appropriate commands to read the optical module information; then when the optical module used in the network card, and how to read the optical module information?
      Next, let us use Moduletek Limited SFP-10G-LR module to access the Intel X520 network card, to show you the operation of the Linux system to read the information on the network card access to the optical module.

Figure 1 Schematic diagram of the optical module connected to the server NIC

1. Optical module status
      Execute the command "ethtool devname" to view the interface information;
      The information output under this command contains interface rate, module rate, module link status (Link detected is yes as a prerequisite for the work of the optical module), and some interface setting information.
      Note: devname is the name of the NIC/port, usually expressed as ethX or pXpX, with X as a number, which can be viewed through the ip or ifconfig commands; it can also be determined according to the slot number on the server panel, for example, p4p1 in the following figure indicates the first interface of the fourth slot.

Figure 2 Optical Module Link Up Status

2. NIC identification of the module and DDM detection data
      Execute the command "ethtool -m devname" to view the information of the optical module on the interface of the device; some NICs do not support this command;
      The information output under this command can be divided into two items, one is the identification information of the optical module, including the module type, wavelength, transmission distance, serial number, vendor name, etc., which originates from the coded data written by the optical module; the other is the DDM data of the optical module, including the diagnosis of real-time data as well as the threshold range, which allows the optical module on the two devices at both ends to be checked whether the working status is normal or not, by focusing on the received optical power, transmitted optical power, temperature value, current value, etc. The information output under this command can be divided into two items. module working status is normal.

Figure 3 Optical module identification and digital diagnosis

      The optical modules provided by Moduletek Limited can be used in various brands of network cards, welcome to buy.
      If you have any questions about the above content, you can contact us by Email : web@moduletek.com