Administration: Discovery
Configuring LLDP
Cisco 220 Series Smart Switches Administration Guide Release 1.1.0.x
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If CDP or LLDP is globally disabled, the switch can be configured to discard,
VLAN-aware flooding, or VLAN-unaware flooding of all incoming CDP or
LLDP packets. VLAN-aware flooding floods an incoming CDP or LLDP
packet to the VLAN where the packet is received excluding the ingress
port. VLAN-unaware flooding floods an incoming CDP or LLDP packet to all
the ports excluding the ingress port. The default is to VLAN-unaware flood
CDP or LLDP packets when CDP or LLDP is globally disabled. You can
configure the discard or flooding of incoming CDP and LLDP packets from
the CDP Properties page and the LLDP Properties page, respectively.
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The 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 on the switch. Refer to the
section for details.
NOTE
CDP or LLDP does not distinguish if a port is in a LAG. If there are
multiple ports in a LAG, CDP or LLDP transmit packets on each port without
taking into account the fact that the ports are in a LAG.
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The operation of CDP or LLDP is independent of the STP status of an
interface.
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If 802.1X port access control is enabled on an interface, the switch will
transmit and receive CDP or 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 or LLDP it is considered
down.
Configuring LLDP
LLDP is a protocol that enables network managers to troubleshoot and enhance
network management in multivendor environments. LLDP standardizes methods
for network devices to advertise themselves to other systems, and to store
discovered information.
LLDP enables a device to advertise its identification, configuration, and
capabilities to neighboring devices that then store the data in a Management
Information Base (MIB). The network management system models the topology of
the network by querying these MIB databases.
LLDP is a link layer protocol. By default, the switch terminates and processes all
incoming LLDP packets as required by the protocol.