LLDP

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