Configuring Cdp Compatibility; Configuration Prerequisites; Configuration Procedure - HP A6600 Configuration Manual

To set the encapsulation format for LLDPDUs to SNAP:
To do...
1. Enter system view
2. Enter
Ethernet
interface
view or
port group
view
3. Set the encapsulation format for
LLDPDUs to SNAP
LLDP-CDP packets use only SNAP encapsulation.

Configuring CDP compatibility

For more information about voice VLANs, see the chapter "Voice VLAN configuration."
To make your router work with Cisco IP phones, you must enable CDP compatibility.
If your LLDP-enabled router cannot recognize CDP packets, it does not respond to the requests of Cisco IP
phones for the voice VLAN ID configured on the router. As a result, a requesting Cisco IP phone sends
voice traffic without any tag to your router, disabling your router from differentiating the voice traffic from
other types of traffic.
With CDP compatibility enabled, your router 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. The voice traffic is
confined in the configured voice VLAN, and differentiated from other types of traffic.

Configuration prerequisites

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

Configuration procedure

The maximum TTL value allowed by CDP is 255 seconds. To make CDP-compatible LLDP work properly
with Cisco IP phones, make 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: The CDP packets can be transmitted and received.
•
Disable: The CDP packets can neither be transmitted nor be received.
•
To make CDP-compatible LLDP take effect on certain ports, first enable CDP-compatible LLDP globally, and
then configure CDP-compatible LLDP to operate in TxRx mode.
Use the command...
system-view
Enter Layer
interface interface-type
2/Layer 3 Ethernet
interface-number
interface view
Enter port group
port-group manual port-group-name
view
lldp encapsulation snap
209
Remarks
—
Required.
Use either command.
Required.
Ethernet II encapsulation
format applies by default.