Fault Symptom
100 MB version files need to be uploaded to more than 10 devices on the network for upgrading the devices. However, it takes more than 20 hours to finish uploading those files to all devices.
Fault Analysis
1. The ping operation shows that the network delay is not long. Therefore, the network is not congested.
2. The speed of uploading version files using the maintenance port on the MPU is normal. Therefore, the CF card is running normally.
3. On the same network, files are uploaded to other devices at a normal speed. Therefore, the other devices are set with no restriction for uploading files.
4. Check upstream LPUs of these devices and find that a bandwidth restriction is set to process FTP packets for security. Therefore, the problem occurs because the devices restrict the rate at which protocol packets are sent to the CPU.
Procedure
1. Run the cpu-defend policy 14 command to create an attack defense policy.
2. Run the car index 61 cir 10000 command to adjust the CIR.
3. Run the quit command to return to the system view.
4. Run the slot 3 command to enter the slot 3 view.
5. Run the cpu-defend-policy 14 command to apply the attack defense policy.
After preceding operations, the bandwidth for processing FTP packets of the board in slot 3 is adjusted to 10 MB. The fault is rectified.
Summary
By default, the device restricts the rate at which protocol packets are sent to the CPU. If the rate at which protocol packets are sent to the CPU is greater than the CIR of the current system, the packets are discarded. Therefore, if the protocol packets cannot be normally uploaded to the CPU by default, you need to adjust the CIR to a larger value to protect the packets from being discarded or restricted.
