LLDP/4/BAD_PACKET
Message
LLDP/4/BAD_PACKET:[ULONG] invalid packets were received after latest notification. The last invalid packet came from interface [STRING].
Description
When a neighbor device is faulty, the format of an LLDP packet may be incorrect. As a result, the network management system (NMS) may not know the topology information. In this case, related information must be recorded and reported. The mechanism is as follows:
If an invalid packet is detected for the first time, an alarm is reported immediately and the invalid packet counter is set to 1.
In the following 30 seconds, if another invalid packet is received, 1 is added to the number of invalid packets.
30 seconds later, if another invalid packet is still received, an alarm containing the number of invalid packets and the port where this invalid packet is received is reported and the invalid packet counter is cleared to zero.
Parameters
| Parameter Name | Parameter Meaning |
|---|---|
| [PacketNumber] | number of invalid packets |
| [InterfaceName] | name of interface where invalid packets are received, for example, GigabitEthernet 1/0/0 |
Possible Causes
Reason 1:
The format of a received LLDP packet is invalid.
Reason 2:
An invalid packet is used for malicious attack.
Procedure
- The administrator can run a command to check whether the
neighbor device connected to the port where an invalid packet is received
is in the normal status.
- In the system view, run display interface to check whether the status of the port is UP.
- If both the local device and the neighbor device enable LLDP, run display lldp local to check whether the link status is UP.
1) If yes, go to step 3.
2) If no, go to step 2.
- Check whether the connection cable is connected properly.
1) If no, connect the cable properly and go to step 4.
2) If yes, go to step 3.
- Check whether there are invalid connections.
1) If yes, remove the cables and go to step 4.
2) If no, go to step 5.
- 30 seconds later, check whether this log still exists in
the log buffer.
1) If yes, go to step 5.
2) If no, go to step 6.
- Collect log information and configuration information, and then contact technical support personnel.
- End.