{{tag>[networking centos]}}
=====Link Layer Discovery Protocol (LLDP) agent daemon=====
If you have a switch that supports LLDP, then you can use the lldpad to send and receive LLDP PDUs.

====Install and enable lldpad====
  yum install lldpad
  chkconfig lldpad on
  service lldpad start

====LLDP settings====
  * -L = set parameters for interface
  * -i = interface
  * -g = bridge scope
<code>
  # enable transmission of information
  lldptool -L -i eth0 adminstatus=rxtx
  
  lldptool -i eth0 -T -V portDesc enableTx=yes
  lldptool -i eth0 -T -V sysName  enableTx=yes
  lldptool -i eth0 -T -V sysDesc enableTx=yes
  lldptool -i eth0 -T -V sysCap enableTx=yes
  lldptool -i eth0 -T -V mngAddr ipv4=192.168.42.66 enableTx=yes
  
  service lldpad restart
</code>

====Query neighbour from command line====
<code>
lldptool -t -n -i eth0

Chassis ID TLV
        MAC: 9c:8e:99:bd:b1:20
Port ID TLV
        Local: 12
Time to Live TLV
        120
Port Description TLV
        Port #12
System Name TLV
        switch1
System Description TLV
         HP ProCurve 1810G - 24 GE, P.2.12, eCos-2.0, CFE-2.1
System Capabilities TLV
        System capabilities:  Bridge
        Enabled capabilities: Bridge
Management Address TLV
        IPv4: 192.168.40.11
        Ifindex: 25
End of LLDPDU TLV

</code>

====View from switch Web GUI====

{{::screenshot_from_2014-05-01_17_27_40.png?nolink|}}

====tcpdump LLDP====
  * Port and CDP Neighbor Info: <code>tcpdump -v -s 1500 -c 1 '(ether[12:2]=0x88cc or ether[20:2]=0x2000)'</code>