L2Man - Cisco Catalyst 4500 Series Message Manual

Chapter 2 Messages and Recovery Procedures

L2MAN

This section contains the L2MAN messages.
Error Message C4K_L2MAN-6-INVALIDSOURCEADDRESSPACKET:Packet received with invalid
source MAC address ( [mac-addr]
Error Message C4K_L2MAN-7-ROUTERMACADDRESSRXASSOURCE: Packet received with my own
MAC address ( [mac-addr]
OL-11541-01
A packet was received with an all zero or a multicast source address. The packet is
Explanation
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.
Recommended Action Check the switch configuration file to find the source of these packets on the
specified port and take corrective action to fix them at the source end. You can also enable port
security on that interface to shutdown the port if the incoming rate of packets with invalid source
mac address is too high by issuing the switchport port-security limit rate invalid-source-mac
<rate> command.
A packet was received with the switch's MAC address as the source address. This MAC
Explanation
was not learned as a valid source address, which suggests that there is a configuration problem. This
message is rate-limited and is displayed only for the first such packet received on any interface or
VLAN. Subsequent messages will display a cumulative count of all such packets received in a given
interval on all interfaces in any VLAN. This usually signifies a loop in your configuration. This
problem can occur in three conditions; L1 loop, L2 loop, or a host with a bogus MAC address is
connected to the switch.
Recommended Action For L1 loop, verify that the physical connection on the port appears in the
syslog message to see if there is a loopback connection. Also use the show cdp neighbor command
to see if the switch is seeing itself.
For L2 loop, first use the show spanning-tree interface <intf> command to make sure spanning
tree is running for that port. Then use the show spanning-tree vlan <vlan-id> command to make
sure the VLAN appears in the syslog on all related switches and confirm that the reported
information (including Bridge ID, blocking ports, port priority, etc) is correct across all the switches
in the topology. If the STP protocol appears to be working, then capture traffic on the blocking ports
to see if it sends traffic. If yes, please contact your technical support representative.
For the third case, determine whether the connected host has its MAC address manually configured
to the value of the switch which shows the syslog message.
Catalyst 4500 Series Switch Cisco IOS System Message Guide Release 12.2(31)SGA
) on port [char]
) as source on port [char]
in vlan [dec]
in vlan [dec]
L2MAN
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