231
Step Command
Remarks
2.
Disable LLDP PVID
inconsistency check.
lldp ignore-pvid-inconsistency
By default, LLDP PVID
inconsistency check is
enabled.
Configuring CDP compatibility
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. Your device cannot differentiate the voice
traffic from other types of traffic.
CDP compatibility enables your device to receive and recognize CDP packets from a Cisco IP phone
and respond with CDP packets carrying TLVs with the voice VLAN configuration. According to TLVs
with the voice VLAN configuration, the IP phone automatically configures the voice VLAN. As a result,
the voice traffic is confined in the configured voice VLAN and is 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 an IP phone.
•
Configure LLDP to operate in Rx or TxRx mode on the port.
Configuration procedure
CDP-compatible LLDP operates in one of the following modes:
•
Rx
mode
—CDP packets can be received but cannot be sent.
•
TxRx
—CDP packets can be transmitted and received.
•
Disable
—CDP packets cannot be transmitted or received.
To make CDP-compatible LLDP take effect on a port, follow these steps:
1.
Enable CDP-compatible LLDP globally.
2.
Configure CDP-compatible LLDP to operate in Rx or TxRx mode on the port.
The maximum TTL value that CDP allows is 255 seconds. To make CDP-compatible LLDP work
correctly with Cisco IP phones, configure the LLDP frame transmission interval to be no more than
1/3 of the TTL value.
To configure LLDP to be compatible with CDP:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enable CDP compatibility
globally.
lldp compliance cdp
By default, CDP compatibility is
disabled globally.
Summary of Contents for H3C S7500E-X
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