lldp tlv-enable med-tlv

Function

The lldp tlv-enable med-tlv command sets to advertise the MED TLVs.

The undo lldp tlv-enable med-tlv command sets the MED TLVs disabled on an interface.

By default, an interface advertises all types of MED TLVs except the Location Identification TLV and Network Policy TLV.

Although the interface does not advertise Network Policy TLV, Network Policy TLV is still enabled.

Format

lldp tlv-enable med-tlv { all | capability | inventory | location-id { civic-address device-type country-code { ca-type ca-value } &<1-10> | elin-address Tel-Number } | network-policy [ voice-vlan { vlan vlan-id [ cos cvalue | dscp dvalue ]^* | 8021p [ cos cvalue | dscp dvalue ]^* | untagged } ] | power-over-ethernet }

undo lldp tlv-enable med-tlv { all | capability | inventory | location-id [ civic-address | elin-address ] | network-policy [ voice-vlan { vlan | cos | dscp | 8021p | untagged } ] | power-over-ethernet }

Parameters

Parameter	Description	Value
all	Indicates that all MED TLVs except Location Identification TLV and Network Policy TLV are advertised.	-
capability	Indicates to advertise MED Capabilities TLV.	-
inventory	Indicates to advertise Hardware Revision TLV, Firmware Revision TLV, Software Revision TLV, Serial Number TLV, Manufacturer Name TLV, Model Name TLV, and Asset ID TLV.	-
location-id	Indicates to advertise Location Identification TLV.	-
civic-address device-type country-code { ca-type ca-value } & <1-10>	Indicates to advertise the common address information of the network devices encapsulated in Location Identification TLV. device-type specifies the type of the device. The value is an integer that ranges from 0 to 2. 0 indicates that the device is a DHCP server. 1 indicates that the device is a switch. 2 indicates that the device is an MED endpoint. country-code specifies the country code. For the value range, see ISO 3166. { ca-type ca-value }&<1-10> specifies the address information. ca-type specifies the type of address information. The value is an integer that ranges from 0 to 255. ca-value specifies the content of the address information. The value is a string of 1-250 characters. <1-10> indicates that the preceding parameters can be entered 10 times.	-
elin-address Tel-Number	Advertises the emergency phone number encapsulated in Location Identification TLV.	The value is a string of 10 to 25 numerals. Each numeral ranges from 0 to 9.
network-policy	Advertises Network Policy TLV. Network Policy TLV is used to exchange VLAN configurations between network devices and terminal devices. A switch uses the TLV to advertise voice VLAN ID and voice stream priority to an IP phone. Then the IP phone forwards packets according to the received voice VLAN ID and priority, ensuring the voice quality. NOTE: An Ethernet interface working in Layer 3 mode does not support the Network Policy TLV.	-
voice-vlan	Encapsulates the voice VLAN ID when advertising Network Policy TLV.	-
vlan vlan-id	Specifies the voice VLAN ID.	The value is an integer that ranges from 1 to 4094.
cos cvalue	Specifies the CoS priority. The CoS priority is the PRI (Priority) field in an 802.1Q VLAN frame. This field is 3 bits long and ensures that high-priority data packets are forwarded first when congestion occurs.	The value is an integer that ranges from 0 to 7. The default value is 5. A larger value indicates a higher priority.
dscp dvalue	Sets the DSCP priority. The first six bits of the Type of Service (ToS) field in an IPv4 packet header are used as the DiffServ Code Point (DSCP). DSCP is used in the DiffServ model to provide QoS guarantee on an IP network. The operations performed by the traffic controller on the gateway are determined only by these six bits.	The value is an integer that ranges from 0 to 63. The default value is 46.
8021p	Sets the voice VLAN ID to VLAN 0.	-
untagged	Configures voice devices to send untagged voice data packets.	-
power-over-ethernet	Advertises Extended Power via MDI TLV.	-

Views

Ethernet interface view, GE interface view, XGE interface view, 25GE interface view, MultiGE interface view, 40GE interface view, 100GE interface view, port group view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

In LLDP, all device information is encapsulated in Link Layer Discovery Protocol data units (LLDPDUs), which are then sent to neighbors. An LLDPDU contains a variety of TLVs. In a TLV, T indicates the information type, L indicates the information length, and V indicates the value or the content to be sent. Devices exchange LLDPDUs carrying TLVs to obtain neighbor information. The TLVs that can be encapsulated in an LLDP packet include basic TLVs, TLVs in the IEEE 802.1 format, TLVs in the IEEE 802.3 format, and MED TLVs. Basic TLVs are essential for managing network devices. The TLVs in the IEEE 802.1 format, TLVs in the IEEE 802.3 format, and MED TLVs are defined by standardization organizations and other organizations, which are used to enhance the network device management. You can determine whether to advertise the IEEE 802.1 format, TLVs in the IEEE 802.3 format, and MED TLVs.

Devices on both ends can have different TLV types configured. You only need to configure TLV types according to networking requirements.

Prerequisites

LLDP has been enabled globally using the lldp enable command.
LLDP has been enabled on the interface using the lldp enable command.

Precautions

When the supported TLVs are MED TLVs, the lldp tlv-enable command with the all parameter advertises all TLVs except Location Identification TLV. If the all parameter is not specified, only one type of TLV can be advertised. To advertise multiple types of TLVs, run this command multiple times.
You can specify the other types of MED TLVs only after specifying the MED Capabilities TLV. To disable the MED Capabilities TLV, first disable the other types of MED TLVs.
To disable the 802.3 MAC/PHY Configuration/Status TLVs, first disable the MED Capabilities TLV.
The 802.3 MAC/PHY Configuration/Status TLVs are automatically advertised after the MED Capabilities TLV is advertised.
If you disable the MED TLVs using the command with the all parameter, the 802.3 MAC/PHY Configuration/Status TLVs are not disabled automatically.
When the switch detects that the LLDP packet sent by an LLDP neighbor on an interface contains any type of MED TLV, the switch advertises all MED TLVs that can be advertised on the interface to the LLDP neighbor. However, the LLDP neighbor may support only parts of MED TLVs advertised by the switch, leading to an LLDP negotiation failure. You can run the undo lldp tlv-enable med-tlv command to enable the interface not to advertise the MED TLV that is not supported by the LLDP neighbor. For example, if a terminal does not support the 802.3af standard, that is, Extended Power-via-MDI TLV cannot be identified, run the undo lldp tlv-enable med-tlv power-over-ethernet command on the interface connected to the terminal to enable the interface not to advertise Extended Power-via-MDI TLV.

Example

# Configure GigabitEthernet0/0/1 to advertise the MED Capabilities TLV.

<HUAWEI> system-view
[HUAWEI] interface gigabitethernet 0/0/1
[HUAWEI-GigabitEthernet0/0/1] lldp tlv-enable med-tlv capability