Through the loopback test, you can check whether the interface has hardware failures. The specific operations are as follows:
1. Internal loopback test of the interface: (without plugging in any network cable, delete all the configurations under the interface at the same time, and clear the statistics under the interface)
Enter the internal loop command in the interface view: loopback internal
Then use the command dis inter xxx to check whether the interface is up.
if it is up, and the input and output data packets of the interface are the same, enter the second step, outer loop test, and delete the inner loop command at the same time.
2. External loopback production: short-circuit 1 and 3, 2 and 6, 4 and 7, 5 and 8 of the crystal head, and the other side is the crystal head, and plug it into the interface to be tested.
External loopback test: Please test on a good port and a bad port respectively (input loopback external under a good interface and then test under the problematic interface after success) to prove that the outer ring head is successful.
Then enter the interface command line and enter:
Then check whether there is a failure message, and check the interface status dis inter xxx to check whether the input and output data packets are consistent.
Remember! The data packet statistics of the interface need to be cleared before and after each test: <h3c>reset counters inter xxx