Configuration Prerequisites; Configuration Procedure - H3C S3600V2 SERIES Layer 2-Lan Switching Configuration Manual

information a bout the display lldp neighbor-information command, see Layer 2—LAN Switching
Command Reference.
To make your device work with Cisco IP phones, you must enable CDP compatibility.
If your LLDP-enabled device cannot recognize CDP packets, it does not respond to the requests of Cisco
IP phones for the voice VLAN ID configured on the device. As a result, a requesting Cisco IP phone sends
voice traffic without any tag to your device, and, as a result, your device cannot differentiate the voice
traffic from other types of traffic.
With CDP compatibility enabled, your device can receive and recognize CDP packets from a Cisco IP
phone and respond with CDP packets, which carry the voice VLAN configuration TLVs. According to the
voice VLAN configuration TLVs, the IP phone automatically configures the voice VLAN. As a result, the
voice traffic is confined in the configured voice VLAN, and differentiated from other types of traffic.
For more information about voice VLANs, see

Configuration prerequisites

Before you configure CDP compatibility, complete the following tasks:
• Globally enable LLDP.
Enable LLDP on the port connecting to a device supporting CDP, and configure the port to operate
•
in TxRx mode.

Configuration procedure

CAUTION:
The maximum TTL value that CDP allows is 255 seconds. To make CDP-compatible LLDP work properly
with Cisco IP phones, be sure that the product of the TTL multiplier and the LLDPDU transmit interval is less
than 255 seconds.
CDP-compatible LLDP operates in one of the follows modes:
• TxRx—CDP packets can be transmitted and received.
Disable—CDP packets cannot be transmitted or received.
•
To make CDP-compatible LLDP take effect on specific ports, first enable CDP-compatible LLDP globally,
and then configure CDP-compatible LLDP to operate in TxRx mode.
To enable LLDP to be compatible with CDP:
Step
1. Enter system view.
2. Enable CDP compatibility
globally.
3. Enter Ethernet interface view
or port group view.
"Configuring a voice
Command
system-view
lldp compliance cdp
•
Enter Layer 2/Layer 3 Ethernet interface
view:
interface interface-type
interface-number
•
Enter port group view:
port-group manual port-group-name
236
VLAN."
Remarks
N/A
Disabled by default.
Use either command.