Troubleshooting and solutions for optical modules in the transmission category

The faults of this type of optical module mainly include port not UP, port status being UP but not receiving or sending messages, frequent port up or down, and CRC errors. The specific troubleshooting methods and solutions for optical modules are as follows:

1. Port not UP

Taking 10G SFP+/XFP optical modules as an example, when the optical port of the optical module cannot be connected to other devices through UP, the following five aspects can be investigated:

The first step is to check if the speed and duplex mode of the two ports match - execute the "show interface brief" command to check. If they do not match, configure the speed and duplex mode of the ports through the speed and duplex commands.

The second step is to check whether the speed and duplex mode of the device port match the optical module - execute the "show interface brief" command to check. If it does not match, configure the speed and duplex mode of the port through the speed command and duplex command.

Step three, check if the ports on both ends are normal - test whether the ports on both ends can be UP through loopback. Use 10G SFP+direct cables (suitable for short distance connections, or use SFP+optical modules and fiber jumpers) on the 10G SFP+port on the single board for interconnection, and use XFP optical modules and fibers on the 10G XFP port for testing to see if the port can UP. If UP is possible, it indicates that the opposite port is abnormal; If UP is not possible, it indicates that the local port is abnormal. The fault can be checked for resolution by replacing the local and opposite ports.

Step 4, check if the optical module is normal - mainly check if the parameters such as DDM, optical power, wavelength, distance, etc. are normal. If they are not normal, replace the optical module that matches the optical interface.

DDM information - Check if the parameters are normal through the "show interfaces transfer detail" command. If an alarm occurs, it indicates that the optical module is faulty or does not match the type of optical interface.

Optical power - Use an optical power meter to test whether the received and emitted power of the port is within the normal range and stable.

Wavelength/Distance - Check whether the wavelength and distance of the two end optical modules are consistent through the "show receiver interface" command.

Step 5, check if the fiber optic is normal - for example, if a single-mode SFP+optical module is paired with a single-mode fiber, or if a multi-mode SFP+optical module is paired with a multi-mode fiber, replace the matching fiber immediately.

If you have not found the cause of the optical module malfunction or resolved the issue according to the above steps, we suggest that you directly contact the supplier's technical personnel for technical assistance.

2.The port status is UP, but it does not receive or send messages

When the port status is up but cannot receive or send messages, troubleshoot from the following three aspects:

The first step is to check the port packet statistics results. Check if the status of the ports on both ends is consistently UP, and check if the packet statistics on both ends are increasing.

Step 2, check if the port configuration affects the reception of messages. Firstly, check if the network configuration has been done, verify if the configuration is correct, and if necessary, delete all before testing to see if the problem is resolved; Secondly, check if the MTU value of the port is 1500. If it is greater than 1500, the configuration needs to be modified.

Step three, check if the port and link cutoff are normal. Replace the connection port and connect it to another port to see if the same phenomenon exists. If the fault persists, replace the optical module.

If the problem with the optical module has not been resolved after following the above steps, it is recommended that you directly contact the supplier's technical personnel.

3. Frequent port up or down

When the optical port of the optical module frequently goes up or down, first confirm whether the optical module is abnormal. You can troubleshoot the issues with the two end optical modules and the connecting fiber by checking the alarm information of the optical module; For optical modules that support digital diagnosis function, the DDM information can be checked to confirm whether the optical power of the optical module is at the critical value. If the transmitted optical power is at the critical value, the fiber and optical module can be replaced as cross validation. If the received optical power is at the critical value, the opposite end optical module and the connecting fiber can be checked. When the electrical port optical module encounters this situation, try setting the rate duplex.

If the optical module fault still exists after troubleshooting the link, peer devices, and intermediate devices, it is recommended that you directly contact the supplier's technical personnel.

4. CRC error

The first step is to check the statistical information of the message to determine the fault problem. By using the "show interface" command, check the error packet statistics in the direction of port entry and exit to determine which volume growth is causing the problem.

CEC, frame, and throttle errors occur in the direction of port entry and the count continues to increase - use an instrument to test if the link is faulty, and if so, replace the network cable or fiber optic; Alternatively, the network cable or fiber optic module can be replaced and connected to other ports. If the wrong packet reappears after the port replacement, it is considered a single board port failure. If the wrong packet still appears after replacing it to a normal port, there is a high possibility of device or intermediate transmission link failure, and troubleshooting is sufficient.

Check if there are any overflow errors in the direction of port input and if the count continues to increase. Execute the "show interface" command multiple times to check if there is an increase in input errors. If there is, it indicates an increase in overflow, which may cause congestion or blockage within the board.

Check if there are any gifts errors in the direction of port entry and if the count continues to increase - check if the Jumbo configuration on both ends is consistent, such as whether the default maximum packet length of the port is consistent, and whether the allowed maximum packet length is consistent.

Step 2, check if the optical power of the optical module is normal. View the current measured values of the digital diagnostic parameters of the optical module inserted into the optical port through the "show receiver interfaces details" command. If the optical power of the optical module is abnormal, the optical module needs to be replaced.

Step three, check if the port configuration is normal. Use the "show interface brief" command to check if there are any abnormalities in the port configuration, where the negotiation status of both ends, duplex mode, and port speed are consistent. If there is half duplex mode or inconsistent speed, use the duplex command and speed command to configure duplex mode and port speed separately.

Step 4, check if the port and link media are functioning properly. Replace the connection port to check if there is a similar phenomenon. If there is a similar phenomenon, check whether the intermediate devices and transmission media in the connection link are normal. If they are normal, replace the optical module.

Step 5, check if the port has received a large number of flow control frames. By using the "show interface" command, check the count of pauses frames on the port. If it continues to increase, it indicates that the port has sent or received a large number of flow control frames. In addition, check whether the incoming and outgoing traffic of the port is too large and the traffic processing capacity of the end device.

After the above inspection, if there are no issues with the configuration, peer, and link, but the optical module fault still exists, please contact the supplier's technical support personnel directly.

Troubleshooting and solutions for optical module faults related to abnormal information reading

1. Display not supported

When checking the system logs, it is found that there is illegal optical module information reported, such as unqualified, unapproved, unknown, etc. Check the coding information first. If there is an error in the coding, re code it. If the coding is correct, contact the supplier's technical support personnel for assistance.

2. DDM not supported

When the system prompts that the optical module does not support digital diagnosis (DDM), use the "show receiver interfaces details" command to check whether the optical module used supports digital diagnosis function, or directly contact the supplier to inquire whether the optical module supports digital diagnosis function. If the module supports digital diagnostic function but cannot solve the problem, directly contact the supplier's technical support personnel for assistance.

3. DDM exception

When the interface for installing the optical module cannot function properly, troubleshooting can be carried out according to the following three steps:

The first step is to check the alarm information of the optical module. If there is a receiving problem in the alarm information, it is generally caused by the opposite port, fiber optic or intermediate equipment; If there is a transmission problem or abnormal current or voltage, it is necessary to investigate the local port.

The second step is to check whether the receiving and transmitting optical power of the optical module is normal. You can use the "show interfaces transfer detail" command to check whether the received/transmitted optical power of the optical module is normal, and whether other parameters are within the threshold range; Alternatively, by conducting real-time queries, check whether parameters such as optical power, temperature, voltage, and bias current are normal.

The third step is to check whether the optical module itself is faulty or if there is a fault in adjacent devices or intermediate connection links. Ports, optical modules, etc. can be replaced for cross validation.

After the above steps, it is still not possible to confirm or solve the optical module fault. You can contact the supplier's technical support personnel for technical assistance.

Troubleshooting and solution methods for hardware optical modules

The troubleshooting of hardware optical modules mainly starts from the optical module itself. Firstly, it is necessary to ensure that the quality of the purchased optical module has been certified. Without certification, the quality cannot be guaranteed, and it is recommended not to use the optical module anymore; Secondly, check if there is any damage to the golden finger of the optical module. If there is any damage, replace the optical module; Finally, check if the interface is contaminated or damaged. If it is contaminated, clean it. If it is damaged, it is recommended to replace it.

summary

In order to greatly reduce the probability of optical module failures during use, it is recommended to choose optical modules with reliable and stable performance and guaranteed quality. At the same time, it is also necessary to understand the correct and professional operation methods, such as network cables, fiber optic jumpers, and other related equipment.