Port Management
UDLD
Cisco 350XG & 550XG Series 10G Stackable Managed Switches
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Dependencies On Other Features
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UDLD and Layer 1.
When UDLD is enabled on a port, UDLD actively runs on that port while the
port is up. When the port is down, UDLD goes into UDLD shutdown state. In
this state, UDLD removes all learned neighbors. When the port is changed
from down to up, UDLD resumes actively running.
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UDLD and Layer 2 Protocols
UDLD runs on a port independently from other Layer 2 protocols running on
the same port, such as STP or LACP. For example, UDLD assigns the port a
status regardless of the STP status of the port or regardless of whether the
port belongs to a LAG or not.
Default Settings and Configuration
The following defaults exist for this feature:
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UDLD is disabled by default on all ports of the device.
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Default message time is 15 seconds.
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Default expiration time is 45 seconds (3 times the message time).
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Default port UDLD state:
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Fiber interfaces are in the global UDLD state.
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Non-fiber interfaces are in the disable state.
Before You Start
No preliminary tasks are required.
