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Catalyst 3750, 3560, 3550, 2975, 2970, and 2960 Switch System Message Guide
OL-8551-04
Chapter 3 Message and Recovery Procedures
DOT1Q_TUNNELLING Messages
Error Message DHCP_SNOOPING_CAT3550-3-UNEXPECTED_EVENT: Process received unknown
event (major [hex], minor [hex]).
Note This message applies to only Catalyst 3550 switches.
Explanation A process received an event it was unable to handle.
Recommended Action Find out more about the error by using the show tech-support privileged
EXEC command and by copying the error message exactly as it appears on the console or system
log and entering it in the Output Interpreter tool. Use the Bug Toolkit to look for similar reported
problems. For more information about these online tools and about contacting Cisco, see the
“Error
Message Traceback Reports” section on page 2-7 for more information.
DOT1Q_TUNNELLING Messages
This section contains the IEEE 802.1Q tunneling message. An incorrect maximum transmission unit
(MTU) setting causes these message.
Error Message DOT1Q_TUNNELLING-4-MTU_WARNING: System MTU of [dec] might be
insufficient for 802.1Q tunnelling. 802.1Q tunnelling requires system MTU size of
[dec] to handle maximum size ethernet frames.
Note This message applies only to Catalyst 3550 switches.
Explanation The switch MTU setting might not be sufficient for IEEE 802.1Q tunneling. The MTU
needs to include the 4-byte overhead associated with the additional IEEE 802.1Q tag. The first [dec]
is the current system MTU setting in bytes, and the second [dec] is the required MTU size in bytes.
Recommended Action Adjust the system MTU for the additional IEEE 802.1Q tag by using the
system mtu global configuration command, and reload the switch by using the reload privileged
EXEC command.
DOT1X Messages
This section contains the IEEE 802.1x messages.
Error Message DOT1X-4-MEM_UNAVAIL: Memory was not available to perform the
802.1X
action.
Explanation The system memory is not sufficient to perform the IEEE 802.1x authentication.
Recommended Action Reduce other system activity to reduce memory demands.
