Debug Udld B - Cisco Catalyst 3550 Command Reference Manual

Appendix B Catalyst 3550 Switch Debug Commands
debug udld
Use the debug udld privileged EXEC command to enable debugging of the UniDirectional Link
Detection (UDLD) feature. Use the no form of this command to disable debugging.
Syntax Description
events
packets
registries
Defaults Debugging is disabled.
Command Modes Privileged EXEC
Command History Release
12.1(4)EA1
Usage Guidelines For debug udld events, these debugging messages appear:
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For debug udld packets, these debugging messages appear:
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For debug udld registries, these categories of debugging messages appear:
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OL-8566-02
debug udld {events | packets | registries}
no debug udld {events | packets | registries}
Display debugging messages for UDLD process events as they occur.
Display debugging messages for the UDLD process as it receives packets
from the packet queue and tries to send them at the request of the UDLD
protocol code.
Display debugging messages for the UDLD process as it processes registry
calls from the UDLD process-dependent module and other feature modules.
Modification
This command was introduced.
General UDLD program logic flow
State machine state changes
Program actions for the set and clear ErrDisable state
Neighbor cache additions and deletions
Processing of configuration commands
Processing of link-up and link-down indications
General packet processing program flow on receipt of an incoming packet
Indications of the contents of the various pieces of packets received (such as type length versions
[TLVs]) as they are examined by the packet reception code
Packet transmission attempts and the outcome
Subblock creation
Fiber-optic port status changes
Catalyst 3550 Multilayer Switch Command Reference
debug udld
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