Configuring Discovery
Configuring LLDP
Cisco 500 Series Stackable Managed Switch Administration Guide
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Auto Smartport requires CDP and/or LLDP to be enabled. Auto Smartport
automatically configures an interface based on the CDP/LLDP
advertisement received from the interface.
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CDP and LLDP end devices, such as IP phones, learn the voice VLAN
configuration from CDP and LLDP advertisements. By default, the switch is
enabled to send out CDP and LLDP advertisement based on the voice
VLAN configured at the switch. Refer to the Voice VLAN and Auto Voice
VLAN sections for details.
NOTE
CDP/LLDP does not distinguish if a port is in a LAG. If there are multiple ports in a
LAG, CDP/LLDP transmit packets on each port without taking into account the fact
that the ports are in a LAG.
The operation of CDP/LLDP is independent of the STP status of an interface.
If 802.1x port access control is enabled at an interface, the switch will transmit and
receive CDP/LLDP packets to and from the interface only if the interface is
authenticated and authorized.
If a port is the target of mirroring, then for CDP/LLDP it is considered down.
NOTE
CDP and LLDP are link layer protocols for directly connected CDP/LLDP capable
devices to advertise themselves and their capabilities. In deployments where the
CDP/LLDP capable devices are not directly connected and are separated with
CDP/LLDP incapable devices, the CDP/LLDP capable devices may be able to
receive the advertisement from other device(s) only if the CDP/LLDP incapable
devices flood the CDP/LLDP packets they receives. If the CDP/LLDP incapable
devices perform VLAN-aware flooding, then CDP/LLDP capable devices can hear
each other only if they are in the same VLAN. It should be noted that a CDP/LLDP
capable device may receive advertisement from more than one device if the CDP/
LLDP incapable devices flood the CDP/LLDP packets.
Configuring LLDP
This section describes how to configure LLDP. It covers the following topics:
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LLDP Overview
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Setting LLDP Properties
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Editing LLDP Port Settings
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LLDP MED