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Error Message Cisco 4500 Switch: C4K_L2MAN-6-INVALIDSOURCEADDRESSPACKET:

I have several Cisco 4500 switches on my network.  I checked the logs and this error message C4K_L2MAN-6-INVALIDSOURCEADDRESSPACKET: Packet received with invalid source MAC address (00:00:00:00:00:00) keeps generating every 24 hrs.  How can this problem be fixed?  Tried disabling IPv6 on end device which didn't fix the problem.

1 REPLY
Cisco Employee

Hi Todd,A packet was received

Hi Todd,

A packet was received with an all zero or a multicast source address. The packet is treated as invalid and no learning is done. Excessive flow of such packets can waste CPU cycles. This message is rate-limited and is displayed only for the first such packet received on any interface or VLAN. Subsequent messages will display cumulative count of all such packets received in given interval on all interfaces.
%C4K_L2MAN-6-INVALIDSOURCEADDRESSPACKET: (Suppressed 1 times)Packet received with invalid source MAC address (00:00:00:00:00:00) on port X

These errors are only informative and are not directly related with the switch. The important thing is to find the source of the packet or the device that is sending the packet.
This indicates that a bad packet was received and was dropped. This could have been sourced as bad packet for different reasons; such as the size of Ethernet frame reported
different from expected IP packet size. The issue can be reported due to bad NIC cards, bad NIC drivers, or bad application.

This message is for informational purpose only. In older IOS versions, these packets are normally dropped without being logged.

If you are receiving a large amount of these errors you might try to track down the source device that is sending the erroneous packets, you'll need to use a network sniffer. You might also examine the adjacent Cisco device for other errors.

HTH

Regards

Inayath

**Plz dont forget to rate if this info is helpfull.

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