CDP, LLDP, Internet of things and POE

The Cisco Discovery Protocol (CDP) is a proprietary Data Link Layer protocol developed by Cisco Systems. It is used to share information about other directly connected Cisco equipment, such as the operating system version and IP address.
This is our connection

 This is what you see using:
# show cdp neighbor

CDP is great but in a mix network environment maybe you want to use something else ..

IEEE802.1AB or LLDP

LLDP is another industry standard protocol that llows network supporting LLDP (that are layer 2 adjacent)to dynamically discover one to another.It's not Cisco proprietary.

We can do more customization with LLDP.It can have a collection of attributes, its called TLV

TLV (Type-Lengh-Value) information:
Information about specific LLDP speaking-device., that can be advertise to a neighbor LLDP speaking device

LLDP is not running on my 3550 switch

Neither on my 2900

The interconnection of multiple devices  that cna be monitored  or controlled trough  a network connection  (a traffic control device, appliances and automation system)


  To accomplish that we will need POE

 Power over Ethernet   describes any of several standardized or ad-hoc systems which pass electrical power along with data on Ethernet cabling. This allows a single cable to provide both data connection and electrical power to devices such as wireless access points or IP cameras. Unlike standards such as Universal Serial Bus which also power devices over the data cables, PoE allows long cable lengths



We have three types of POE standars

• Cisco inline power,  the original one
•  IEEE 802.3af PoE standard provides up to 15.4 W of DC power (minimum 44 V DC and 350 mAto each deviceOnly 12.95 W is assured to be available at the powered device as some power dissipates in the cable

•  IEEE 802.3at  PoE standard also known as PoE+ or PoE plus, provides up to 25.5 W of power.The 2009 standard prohibits a powered device from using all four pairs for power.

How to verify POE on Cysco Catalyst switch



switch3550#conf t
switch3550#int range fa0/5-6
switch3550#power inline auto ?
switch3550#power inline auto max  ?  (maximum amount of power)
switch3550#power inline auto
switch3550#end

 Unfortunately our switch 3550 doesn't have the capacity to show power inline commands

This is how you keep  an eye on your power budget