Management and Configuration Guide K/KA/KB.15.15

Mandatory Data
An active LLDP port on the switch always includes the mandatory data in its outbound advertisements.
LLDP collects the mandatory data, and, except for the Remote Management Address, you cannot
use LLDP commands to configure the actual data.
• Chassis Type (TLV subelement)
• Chassis ID (TLV)
• Port Type (TLV subelement)
• Port ID (TLV)
• Remote Management Address (TLV; actual IP address is a subelement that can be a default
address or a configured address)
Optional Data
You can configure an individual port or group of ports to exclude one or more of the following
data types from outbound LLDP advertisements.
• Port description (TLV)
• System name (TLV)
• System description (TLV)
• System capabilities (TLV)
System capabilities Supported (TLV subelement)•
• System capabilities Enabled (TLV subelement)
• Port speed and duplex (TLV subelement)
Optional data types, when enabled, are populated with data internal to the switch; that is, you
cannot use LLDP commands to configure their actual content.
Support for port speed and duplex advertisements
This feature is optional for LLDP operation, but is required for LLDP-MED operation.
Port speed and duplex advertisements are supported on the switches to inform an LLDP endpoint
and the switch port of each other's port speed and duplex configuration and capabilities.
Configuration mismatches between a switch port and an LLDP endpoint can result in excessive
collisions and voice quality degradation. LLDP enables discovery of such mismatches by supporting
SNMP access to the switch MIB for comparing the current switch port and endpoint settings.
(Changing a current device configuration to eliminate a mismatch requires intervention by the
system operator.)
An SNMP network management application can be used to compare the port speed and duplex
data configured in the switch and advertised by the LLDP endpoint. You can also use the CLI to
display this information.
Port VLAN ID TLV support on LLDP
The port-vlan-id option enables advertisement of the port VLAN ID TLV as part of the regularly
advertised TLVs. This allows discovery of a mismatch in the configured native VLAN ID between
LLDP peers. The information is visible using show commands and is logged to the Syslog server.
SNMP support
The LLDP-EXT-DOT1-MIB has the corresponding MIB variables for the Port VLAN ID TLV. The TLV
advertisement can be enabled or disabled using the MIB object
lldpXdot1ConfigPortVlanTxEnable in the lldpXdot1ConfigPortVlanTable.
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