Solution - HPE FlexNetwork 10500 SERIES Troubleshooting Manual

Solution

Possible reasons for high CPU usage problems include:
•
Route flapping is taking place.
•
The device is being attacked.
•
A link loop exists. A link loop might cause broadcast storm and network flapping problems. If
such a problem occurs, large amounts of protocol packets are sent to the CPU. Many interfaces
on the device receive heavy traffic. The interface usage might reach 90% or be even higher.
To resolve the problem:
1. Display routing table information multiple times. If route entries change frequently, route
flapping is taking place. Go to step 7.
2. Verify that the device is not being attacked:
a. Use a packet capture tool to capture packets on ports of the device. For example, you can
use Sniffer, Wireshark, or WinNetCap.
b. Analyze packet characteristics to identify the attack sources.
c. Configure attack prevention against the attack sources.
For more information, see Security Configuration Guide.
3. Verify that no link loops exist:
a. Display interface information to view the inbound packet statistics for interfaces on the
device.
<Sysname> display interface gigabitethernet3/0/1
GigabitEthernet3/0/1
Current state: UP
Line protocol state: UP
Description: GigabitEthernet3/0/1 Interface
Bandwidth: 1000000 kbps
Maximum transmission unit: 1500
Internet address: 2.1.1.2/24 (primary)
IP packet frame type: Ethernet II, hardware address: 0000-fc00-9276
IPv6 packet frame type: Ethernet II, hardware address: 0000-fc00-9276
Loopback is not set
Media type is twisted pair, port hardware type is 1000_BASE_T
Port priority: 0
1000Mbps-speed mode, full-duplex mode
Link speed type is autonegotiation, link duplex type is autonegotiation
Flow-control is not enabled
Maximum frame length: 9216
Last clearing of counters: Never
Peak input rate: 8 bytes/sec, at 2016-03-19 09:20:48
Peak output rate: 1 bytes/sec, at 2016-03-19 09:16:16
Last 300 second input: 26560 packets/sec 123241940 bytes/sec 99%
Last 300 second output: 0 packets/sec 0 bytes/sec 0%
......
If the interface usage is 90% or higher, a link loop exists.
b. If a link loop exists, perform the following tasks:
− Verify that relevant links are correctly connected.
− Verity that relevant interfaces are correctly configured.
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