NOTE:
LLDP-MED operation also requires the port speed and duplex TLV (dot3TlvEnable), which is enabled
in the default configuration.
Topology change notifications provide one method for monitoring system activity. However, because
SNMP normally employs UDP, which does not guarantee datagram delivery, topology change
notification should not be relied upon as the sole method for monitoring critical endpoint device
connectivity.
LLDP-MED fast start control
Syntax:
lldp fast-start-count <1-10>
An LLDP-MED device connecting to a switch port may use the data contained in the MED TLVs from the switch to
configure itself. However, the
lldp refresh-interval
setting (default: 30 seconds) for transmitting
advertisements can cause an unacceptable delay in MED device configuration.
To support rapid LLDP-MED device configuration, the
lldp fast-start-count
command temporarily
overrides the
refresh-interval
setting for the
fast-start-count
advertisement interval. This results in the
port initially advertising LLDP-MED at a faster rate for a limited time. Thus, when the switch detects a new LLDP-
MED device on a port, it transmits one LLDP-MED advertisement per second out the port for the duration of the
fast-start-count
interval. In most cases, the default setting should provide an adequate
fast-start-
count
interval.
(Default: 5 seconds)
NOTE:
This global command applies only to ports on which a new LLDP-MED device is detected. It does not
override the
refresh-interval
setting on ports where non-MED devices are detected.
Advertising device capability, network policy, PoE status and location data
The medTlvEnable option on the switch is enabled in the default configuration and supports the following LLDP-
MED TLVs:
• LLDP-MED capabilities: This TLV enables the switch to determine:
◦ Whether a connected endpoint device supports LLDP-MED
◦ Which specific LLDP-MED TLVs the endpoint supports
◦ The device class (1, 2, or 3) for the connected endpoint
This TLV also enables an LLDP-MED endpoint to discover what LLDP-MED TLVs the switch port currently
supports.
• Network policy operating on the port to which the endpoint is connected (VLAN, Layer 2 QoS, Layer 3 QoS)
• PoE (MED Power-over-Ethernet)
• Physical location data (see
Configuring location data for LLDP-MED devices
on page 238)
Chapter 7 Configuring for Network Management Applications
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