Cisco 350XG series Administration Manual page 137

Administration: Discovery
LLDP and CDP
NOTE
NOTE
Cisco 350XG & 550XG Series 10G Stackable Managed Switches
• If CDP/LLDP is globally disabled, the device can be configured to discard,
VLAN-aware flooding, or VLAN-unaware flooding of all incoming CDP/LLDP
packets. VLAN-aware flooding floods an incoming CDP/LLDP packet to the
VLAN where the packet is received excluding the ingress port. VLAN-
unaware flooding floods an incoming CDP/LLDP packet to all the ports
excluding the ingress port. The default is to discard CDP/LLDP packets
when CDP/LLDP is globally disabled. You can configure the discard/
flooding of incoming CDP and LLDP packets from the
and the LLDP Properties
• 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.
• CDP and LLDP end devices, such as IP phones, learn the voice VLAN
configuration from CDP and LLDP advertisements. By default, the device is
enabled to send out CDP and LLDP advertisement based on the voice
VLAN configured at the device. Refer to the
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 device transmits and
receives 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 CDP/LLDP considers it down.
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 receive. 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. A CDP/LLDP-capable device may
receive advertisements from more than one device if the CDP/LLDP-incapable
devices flood the CDP/LLDP packets.
page, respectively.
Voice VLAN
9
CDP Properties page
for details.
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