Configuring LLDP

This chapter contains the following sections:

Configuring Global LLDP Commands

You can set global LLDP settings. These settings include the length of time before discarding LLDP information received from peers, the length of time to wait before performing LLDP initialization on any interface, the rate at which LLDP packets are sent, the port desription, system capabilities, system description, and system name.

LLDP supports a set of attributes that it uses to discover neighbor devices. These attributes contain type, length, and value descriptions and are referred to as TLVs. LLDP supported devices can use TLVs to receive and send information to their neighbors. Details such as configuration information, device capabilities, and device identity can be advertised using this protocol.

The switch supports the following required management LLDP TLVs:
  • Data Center Ethernet Parameter Exchange (DCBXP) TLV
  • Management address TLV
  • Port description TLV
  • Port VLAN ID TLV ((IEEE 802.1 organizationally specific TLVs)
  • System capabilities TLV
  • System description TLV
  • System name TLV

The Data Center Bridging Exchange Protocol (DCBXP) is an extension of LLDP. It is used to announce, exchange, and negotiate node parameters between peers. DCBXP parameters are packaged into a specific DCBXP TLV. This TLV is designed to provide an acknowledgement to the received LLDP packet.

DCBXP is enabled by default, provided LLDP is enabled. When LLDP is enabled, DCBXP can be enabled or disabled using the [no] lldp tlv-select dcbxp command. DCBXP is disabled on ports where LLDP transmit or receive is disabled.

To configure LLDP settings, perform this task:

Before You Begin

Ensure that the LLDP feature is enabled on the switch.

Procedure
      Command or Action Purpose
    Step 1 switch# configure terminal
     

    Enters configuration mode.

     
    Step 2 switch(config)# lldp {holdtime seconds | reinit seconds | timer seconds | tlv-select {dcbxp | management-address | port-description | port-vlan | system-capabilities | system-description | system-name}}
     

    Configures LLDP options.

    Use the holdtime option to set the length of time (10 to 255 seconds) that a device should save LLDP information received before discarding it. The default value is 120 seconds.

    Use the reinit option to set the length of time (1 to 10 seconds) to wait before performing LLDP initialization on any interface. The default value is 2 seconds.

    Use the timer option to set the rate (5 to 254 seconds) at which LLDP packets are sent. The default value is 30 seconds.

    Use the tlv-select option to specify the type length value (TLV). The default is enabled to send and receive all TLVs.

    Use the dcbxp option to specify the Data Center Ethernet Parameter Exchange (DCBXP) TLV messages.

    Use the managment-address option to specify the management address TLV messages.

    Use the port-description option to specify the port description TLV messages.

    Use the port-vlan option to specify the port VLAN ID TLV messages.

    Use the system-capabilities option to specify the system capabilities TLV messages.

    Use the system-description option to specify the system description TLV messages.

    Use the system-name option to specify the system name TLV messages.

     
    Step 3 switch(config)# no lldp {holdtime | reinit | timer}
     

    Reset the LLDP values to their defaults.

     
    Step 4 (Optional)switch#show lldp 

    Displays LLDP configurations.

     

    This example shows how to configure the global LLDP hold time to 200 seconds: 

    switch# configure terminal
switch(config)# lldp holdtime 200
switch(config)#

    This example shows how to to enable LLDP to send or receive the management address TLVs:

    switch# configure terminal
switch(config)# lldp tlv-select management-address
switch(config)#

    Configuring Interface LLDP Commands

    To configure the LLDP feature for a physical Ethernet interface, perform this task:

    Procedure
        Command or Action Purpose
      Step 1 switch# configure terminal
       

      Enters configuration mode.

       
      Step 2 switch(config)# interface type slot/port
       

      Selects the interface to change.

       
      Step 3 switch(config-if)# [no] lldp {receive | transmit}
       

      Sets the selected interface to either receive or transmit.

      The no form of the command disables the LLDP transmit or receive.

       
      Step 4 (Optional)switch#show lldp 

      Displays LLDP configurations.

       

      This example shows how to set an interface to transmit LLDP packets: 

      switch# configure terminal
      switch(config)# interface ethernet 1/2
      switch(config-if)# lldp transmit

      This example shows how to configure an interface to disable LLDP: 

      switch# configure terminal
      switch(config)# interface ethernet 1/2
      switch(config-if)# no lldp transmit
      switch(config-if)# no lldp receive

      This example shows how to display LLDP interface information: 

      switch# show lldp interface ethernet 1/2
      tx_enabled: TRUE
      rx_enabled: TRUE
      dcbx_enabled: TRUE
      Port MAC address:    00:0d:ec:a3:5f:48
      Remote Peers Information
      No remote peers exist

      This example shows how to display LLDP neighbor information: 

      switch# show lldp neighbors
      LLDP Neighbors
       
      Remote Peers Information on interface Eth1/40
      Remote peer's MSAP: length 12 Bytes:
      00    c0    dd    0e    5f    3a    00    c0    dd    0e    5f    3a
       
      LLDP TLV's
      LLDP TLV type:Chassis ID  LLDP TLV Length: 7
      LLDP TLV type:Port ID  LLDP TLV Length: 7
      LLDP TLV type:Time to Live  LLDP TLV Length: 2
      LLDP TLV type:LLDP Organizationally Specific  LLDP TLV Length: 55
      LLDP TLV type:LLDP Organizationally Specific  LLDP TLV Length: 5
      LLDP TLV type:END of LLDPDU  LLDP TLV Length: 0
       
      Remote Peers Information on interface Eth1/34
      Remote peer's MSAP: length 12 Bytes:
      00    0d    ec    a3    27    40    00    0d    ec    a3    27    69
       
      LLDP TLV's
      LLDP TLV type:Chassis ID  LLDP TLV Length: 7
      LLDP TLV type:Port ID  LLDP TLV Length: 7
      LLDP TLV type:Time to Live  LLDP TLV Length: 2
      LLDP TLV type:LLDP Organizationally Specific  LLDP TLV Length: 55
      LLDP TLV type:LLDP Organizationally Specific  LLDP TLV Length: 5
      LLDP TLV type:END of LLDPDU  LLDP TLV Length: 0
       
      Remote Peers Information on interface Eth1/33
      Remote peer's MSAP: length 12 Bytes:
      00    0d    ec    a3    27    40    00    0d    ec    a3    27    68
       
      LLDP TLV's
      LLDP TLV type:Chassis ID  LLDP TLV Length: 7
      LLDP TLV type:Port ID  LLDP TLV Length: 7
      LLDP TLV type:Time to Live  LLDP TLV Length: 2
      LLDP TLV type:LLDP Organizationally Specific  LLDP TLV Length: 55
      LLDP TLV type:LLDP Organizationally Specific  LLDP TLV Length: 5
      LLDP TLV type:END of LLDPDU  LLDP TLV Length: 0

      This example shows how to display LLDP timer information: 

      switch# show lldp timers
      LLDP Timers
      holdtime 120 seconds
      reinit 2 seconds
      msg_tx_interval 30 seconds

      This example shows how to display LLDP counters: 

      switch# show lldp traffic
      LLDP traffic statistics:
       
          Total frames out: 8464
          Total Entries aged: 6
          Total frames in: 6342
          Total frames received in error: 2
          Total frames discarded: 2
          Total TLVs unrecognized: 0

      MIBs for LLDP

      MIB MIB Link
      LLDP-MIB

      To locate and download MIBs, go to the following URL:

      http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml