Management and Configuration Guide K/KA/KB.15.15
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.
NOTE: LLDP-MED operation requires the macphy_config TLV subelement (enabled by default)
that is optional for IEEE 802.1AB LLDP operation. For more information, see the dot3TlvEnable
macphy_config command.
Network policy advertisements
Network policy advertisements are intended for real-time voice and video applications, and include
these TLV subelements:
• Layer 2 (802.1p) QoS
• Layer 3 DSCP (diffserv code point) QoS
• Voice VLAN ID (VID)
VLAN operating rules
These rules affect advertisements of VLANs in network policy TLVs:
• The VLAN ID TLV subelement applies only to a VLAN configured for voice operation ( vlan
vid voice.)
• If there are multiple voice VLANs configured on a port, LLDP-MED advertises the voice VLAN
having the lowest VID.
• The voice VLAN port membership configured on the switch can be tagged or untagged.
However, if the LLDP-MED endpoint expects a tagged membership when the switch port is
configured for untagged, or the reverse, a configuration mismatch results. (Typically, the
endpoint expects the switch port to have a tagged voice VLAN membership.)
• If a given port does not belong to a voice VLAN, the switch does not advertise the VLAN ID
TLV through this port.
Policy elements
These policy elements may be statically configured on the switch or dynamically imposed during
an authenticated session on the switch using a RADIUS server and 802.1X or MAC authentication.
(Web authentication does not apply to VoIP telephones and other telecommunications devices that
are not capable of accessing the switch through a Web browser.) The QoS and voice VLAN policy
elements can be statically configured with the following CLI commands:
vlan vid voice
vlan vid tagged | untagged
260 Configuring for Network Management Applications