NE5000E attaches BAS through GE interface. BAS access users have many types of service. Configure more than 13 sub-interfaces on GE interface of NE5000E and OSPF protocol is enabled on each sub-interface (It is configured as silent-interface.). One day NE5000E attached BAS access users complains they access network slowly. Remote log: NE5000E responds slowly for terminal command. With display health and it is found that CPU usage reaches more than 85%.
NE5000E version: 5.10-02J.08
There is much up/down information of one GE interface in the log of NE5000E.
1. Check CPU usage of MPU board and it is high.
Slot CPU Usage Memory Usage (Used/Total)
17 MPU(Master) 87% 19% 172MB/889MB
1 LPU 7% 32% 126MB/390MB
2 LPU 7% 32% 126MB/390MB
5 LPU 11% 30% 119MB/390MB
6 LPU 17% 37% 147MB/390MB
18 MPU(Slave) 2% 14% 128MB/889MB
2. Check whether there is abnormal log and it is found that one GE port is frequently UP/DOWN.
3. Shutdown the problematic port and CPU of MPU is normal.
4. The port is new. Optical module of NE5000E and that of BAS mismatch. The interface is frequently UP/DOWN. Change optical module and it is normal.
NE5000E attached BAS GE interface configures more than 13 subinterfaces. OSPF is enabled on each interface. When the interface flaps, it is the same as GE interface that does not configure sub-interface. OSPF module of MPU board upgrades related interface. OSPF module of MPU is too busy and CPU usage of MPU is high.
During the operation of network device, interface up/down is common because of optical channel. When the interface is not often up/down, it has little influence on the router. When the interface is frequently up/down and the interface configures much sub-interface, it will exhaust much handling of MPU. The CPU of MPU is high and even influences routing upgrade of the router and causes network event. Now Huawei NE5000E does not support punishment mechanism when GE interface is frequently up/down. The problem cannot be completely solved. It can temporarily solved by shutdown problematic port.