# LLDP

### 1. Function Overview

LLDP is a protocol for passing device management information between a device and its neighboring devices.

### 2. Definition of Terms Used

LLDP

Link Layer Discovery Protocol.
This is defined in IEEE 802.1AB.

LLDP-MED

LLDP for Media Endpont Devices.
This is defined in ANSI/TIA-1057.

### 3. Function Details

#### 3.1. Operating specifications

##### 3.1.1. Basic specifications

This product supports the following operations.

- LLDP frames are transmitted from any LAN port to convey information about the device itself.

- LLDP frames are received at any LAN port to obtain information about neighboring devices.

LLDP sends and receives information using Type, Length, and Value (TLV) attributes.
For details on the TLV information sent by this product, refer to TLV list.

The following settings are required in order to use the LLDP function.

- Enable LLDP functionality for the overall system using the lldp run command.

- Create LLDP agents at applicable interfaces using the lldp-agent command.

- Specify the LLDP frame transmit/receive mode using the set lldp command.

The LLDP function is enabled in default settings for this product.

LLDP frames are always transmitted without tags, regardless of the VLAN settings of the transmitting switch port.
They are also transmitted without tags from a trunk port without a native VLAN.

##### 3.1.2. Transmitted information settings

In this product, only the type of management address to be sent in the basic management TLVs can be set using the set management-address-tlv command. Any other transmitted information cannot be changed.

The LLDP frames to be sent from the device itself always contain the following TLVs. For details, refer to 3.2 TLV list.

- Required TLVs

- Basic management TLVs

- IEEE 802.1 TLV

- IEEE 802.3 TLV

- LLDP-MED TLV (only when an LLDP frame containing an LLDP-MED TLV is received from a neighboring device)

##### 3.1.3. Transmission timer setting

LLDP frame transmission interval is specified by the set timer msg-tx-interval command.
The multiplier for calculating the hold time (TTL) for device information is set by the set msg-tx-hold command.
The TTL for LLDP transmission is the result of the following calculation. The default is 121 seconds.

- TTL = ( value set by the “set timer msg-tx-interval” command ) × ( value set by the “set msg-tx-hold” command ) + 1 (second)

##### 3.1.4. Maximum connected devices setting

The maximum number of connected devices that can be managed by the corresponding port is set by the set too-many-neighbors limit command.
The default value for the maximum number of connected devices is 5 devices.

##### 3.1.5. Checking LLDP information

LLDP interface settings and received information about neighbor devices can be checked by using the show lldp interface command or the show lldp neighbors command.

To clear the LLDP frame counter, use the clear lldp counters command.

#### 3.2. TLV list

The TLVs supported by this product are listed below.

- Required TLVs

- Basic management TLVs

- IEEE 802.1 TLV

- IEEE 802.3 TLV

- LLDP-MED TLV

For detailed specifications of each TLV, refer to IEEE 802.1AB (LLDP) and ANSI/TIA-1057 (LLDP-MED).
The TLVs that are transmitted by this product are explained below.

##### 3.2.1. Required TLVs

These are TLVs that LLDP-compliant devices always transmitted.
Three TLVs are transmitted: chassis ID, port ID, and TTL.
The required TLVs are listed below.

Type | Description | Length | Value (only fixed values are listed)
--- | --- | --- | ---
Chassis ID | Chassis ID | 6 bytes | MAC address of the device
Port ID | Port ID | 7 to 8 bytes | Port name (port1.X)
Time To Live (TTL) | Hold time of device information (sec) | 2 bytes |

##### 3.2.2. Basic management TLVs

These TLVs contain system-related management information such as name, system capabilities, and address.
The basic management TLVs are listed below.

Type | Description | Length | Value (only fixed values are listed)
--- | --- | --- | ---
Port Description | Port description string | 7 to 8 bytes |
System Name | System name string | 10 to 10 bytes |
System Description | System description string | 28 bytes | SWX2210P-XXG Rev.1.03.XX
System Capabilities | Capabilities supported by the system | 2 bytes | 0x0004（bridge）
Enabled system capabilities | 2 bytes | 0x0004（bridge）
Management Address | Management address IP address (4 bytes) or MAC address (6 bytes) | 4 or 6 bytes |
Interface sub-type | 1 byte | 0x02 (ifIndex)
Interface number | 1 to 2 bytes | ifIndex value

##### 3.2.3. IEEE 802.1 TLV

These TLVs contain information such as the VLAN and link aggregation for the corresponding port.
The IEEE 802.1 TLVs are listed below.

Type | Description | Length | Value (only fixed values are listed)
--- | --- | --- | ---
Port VLAN ID | Port VLAN number | 2 bytes |
Port and Protocol VLAN ID | Protocol VLAN support and enable/disable | 1 byte | 0x00 (no support)
Protocol VLAN number | 2 bytes | 0x0000
Protocol Identity | Byte string that identifies the protocol | 0 to 255 bytes |
Link Aggregation | Aggregation capability and status | 2 bytes |
ifIndex number of aggregation logical interface | 1 to 2 bytes |
VLAN Name | Name of the VLAN to which the port belongs | 0 to 32 bytes |

##### 3.2.4. IEEE 802.3 TLV

These TLVs are used for transmitting information such as the auto negotiation support information and maximum frame size information for the corresponding port.
The IEEE 802.3 TLVs are listed below.

Type | Description | Length | Value (only fixed values are listed)
--- | --- | --- | ---
MAC/PHY Configuration/Status | Auto negotiation support, and whether enabled or disabled | 1 byte |
Supported communication method for auto negotiation | 2 bytes | LAN port: 0x6C01 (10/100/1000M)
Operational MAU Type Data signaling rate and duplex mode (IETF RFC 4836) | 2 bytes |
Power Via MDI | MDI power support status | 1 byte |
PSE power pair Selection of wiring to be used for power supply | 1 byte | 0x01 (signal line)
Power class Class0 to Class4 | 1 byte |
Power type PSE Device/PD Device | 2 bit | 0b00 (PSE Device)
Power source Primary/Secondary | 2 bit | 0b01 (Primary)
Priority | 2 bit |
Power required from PD device (in units of 0.1 watts) | 2 bytes |
Power supply of PSE device (in units of 0.1 watts) | 2 bytes |
Maximum Frame Size | Maximum frame size | 2 bytes |

##### 3.2.5. LLDP-MED TLV

If an LLDP frame containing an LLDP-MED TLV is received from a neighboring device, this TLV will also be contained in the LLDP frame sent from this product.
The LLDP-MED TLVs are listed below.

Type | Description | Length | Value (only fixed values are listed)
--- | --- | --- | ---
LLDP-MED Capabilities | Transmittable LLDP-MED TLVs | 2 bytes | 0x0009 (LLDP-MED Capabilities, Extended Power-via-MDI TLV )
Device type | 1 byte | 0x04 (Network Connectivity)
Extended Power-via-MDI | Power type PSE Device/PD Device | 2 bit | 0b00 (PSE Device)
Power source Primary/Secondary | 2 bit | 0b01 (Primary)
Power priority | 4 bit |
Power required from PD (in units of 0.1 watts) | 2 bytes |

### 4. Related Commands

Related commands are indicated below.
For details, refer to the Command Reference.

Operations | Operating commands
--- | ---
Enable LLDP function | lldp run
Create LLDP agent | lldp-agent
Set LLDP transmission/reception mode | set lldp
Set the type of management address | set management-address-tlv
Set the LLDP frame transmission interval | set timer msg-tx-interval
Set the multiplier for calculating the hold time (TTL) for device information | set msg-tx-hold
Set the maximum number of connected devices that can be managed by each port | set too-many-neighbors limit
Show interface status | show lldp interface
Show connected device information for all interfaces | show lldp neighbors
Clear LLDP frame counters | clear lldp counters

### 5. Examples of Command Execution

#### 5.1. Set LLDP frame transmission/reception

For port1.1, enable LLDP frame transmission/reception.
Set the LLDP frame transmission interval to 60 seconds. Set the LLDP frame TTL to 181 seconds.
Specify 10 as the maximum number of connected devices managed by the port.

    Yamaha#configure terminal
    Yamaha(config)#interface port1.1
    Yamaha(config-if)#lldp-agent (1)
    Yamaha(lldp-agent)#set timer msg-tx-interval 60 (2)
    Yamaha(lldp-agent)#set msg-tx-hold 3 (3)
    Yamaha(lldp-agent)#set too-many-neighbors limit 10 (4)
    Yamaha(lldp-agent)#set lldp enable txrx (5)
    Yamaha(lldp-agent)#exit
    Yamaha(config-if)#exit
    Yamaha(config)#lldp run (6)
    Yamaha(config)#exit

1 | Create LLDP agent, mode transition
2 | Set transmission interval
3 | Set multiplier for TTL calculation: TTL = 60 x 3 + 1 = 181 seconds
4 | Maximum connected devices setting
5 | Set LLDP transmission/reception mode
6 | Enable LLDP function

#### 5.2. Show LLDP interface status

Show the port1.1 LLDP interface information.

    Yamaha#show lldp interface port1.1 (1)
    Agent Mode                          : Nearest bridge
    Enable (tx/rx)                      : Y/Y
    Message fast transmit time          : 1
    Message transmission interval       : 60
    Reinitialisation delay              : 2
    MED Enabled                         : Y
    Device Type                         : NETWORK_CONNECTIVITY
    LLDP Agent traffic statistics
      Total frames transmitted          : 1
      Total entries aged                : 0
      Total frames received             : 0
      Total frames received in error    : 0
      Total frames discarded            : 0
      Total discarded TLVs              : 0
      Total unrecognised TLVs           : 0

1 | Show interface information

#### 5.3. Show LLDP connected device information

Show LLDP connected device information.

    Yamaha#show lldp neighbors (1)
    Interface Name                  : port1.1
    System Name                     : SWX2210P
    System Description              : SWX2210P-28G Rev.1.03.13
    Port Description                : port1.1
    System Capabilities             : L2 Switching
    Interface Numbering             : 2
    Interface Number                : 5001
    OID Number                      :
    Management IP Address           : 192.168.100.241
    Mandatory TLVs
      CHASSIS ID TYPE
        Chassis MAC ADDRESS         : ac44.f284.ef22
      PORT ID TYPE
        INTERFACE NAME              : port1.1
      TTL (Time To Live)            : 121
    8021 ORIGIN SPECIFIC TLVs
      Port Vlan id                  : 1
      PP Vlan id                    : 0
      Remote VLANs Configured
        VLAN ID                     : 1
        VLAN Name                   : default
      Remote Protocols Advertised:
        IPv4
      Remote VID Usage Digest       : 0
      Remote Management Vlan        : 0
    8023 ORIGIN SPECIFIC TLVs
      AutoNego Support              : Supported Enabled
      AutoNego Capability           : 27649
      Operational MAU Type          : 30
      Power via MDI Capability (raw data)
        MDI power support           : 0x2
        PSE power pair              : 0x1
        Power class                 : 0x0
        Type/source/priority        : 0x0/0x1/0x3
        PD requested power value    : 0.0 W
        PSE allocated power value   : 0.0 W
      Link Aggregation Status       : Disabled
      Link Aggregation Port ID      : 0
      Max Frame Size                : 1522

1 | Show connected device information

### 6. Points of Caution

None

### 7. Related Documentation

None

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