What are the possible causes when the traffic diagram changes greatly in
Possible causes are as follows:
1. An NAT address pool is configured but no corresponding black-hole route is
configured. Route loops cause a large number of expired packets. The firewall
protects the CPU of the MPU and performs CAR for uplink traffic, which affects
traffic sampling by the NMS.
Solution: Configure black-hole routes for the NAT address pool.
2. A large number of expired packets exist on the network.
Solution: Configure tracert attack defense.
[USG9000] firewall defend tracert enable
3. Packets are discarded, which causes traffic loss in the NMS.
Confirmation method: Ping the interface IP address of the firewall on the NMS
server to check whether packet loss occurs.
4. The time actually taken by the NMS to collect data exceeds the preset
collection period. For example, if the collection period is set to 5 minutes
but the NMS takes 6 minutes to collect all data, the data collected is
Solution: Combine the MIB nodes from which information is to be collected in a
single request message. This reduces the number of sent packets and therefore
decreases the time required to collect data each time.