Cisco Discovery Protocol
c000.0800.0000 for 802.5
Use of multicast address
Cisco Discovery Protocol uses IEEE 802.2 and 802.3 encapsulation only.
LLDP has a dedicated ethertype: 88-CC.
Subnetwork Access Protocol (SNAP) value
Token Ring support
Fiber Distributed Data Interface (FDDI) support
No (not formalized)
No (not formalized)
Frame Relay support
Fast Start support
There is no difference in protocol operation, although of course different device types may transmit different TLVs.
LDDP-MED is used only between network devices (such as switches) and endpoint devices (such as phones).
This MIB includes the following:
Topology change notification
Local device information
Remote device information
Topology change notification-Sends a notification if a device is added or removed
The switch does not accept or send Cisco Discovery Protocol packets until after
The switch does not accept or send LLDP-MED packets until after authentication occurs.
Standard 802.1x interaction
Default 60 seconds
Default 30 seconds
Advertising frequency (time between
Transmit frame on local MIB change-If one of the settings in the local MIB changes
Accept (all Cisco equipment supports Cisco Discovery Protocol); note, of course, that if
Cisco Discovery Protocol is disabled then these
Accept, depending on products, the timeframe,
and configuration; LLDP-MED is not planned for introduction on all existing endpoint products,
and the rollout schedule may vary from product
Cisco device action on receiving an LLDP-MED or Cisco Discovery Protocol frame
Most switches ignore the Cisco Discovery Protocol messages but forward them.
Accept, depending on their support for LLD-MED and configuration
Third-party device action on receiving an LLDP-MED or Cisco Discovery Protocol
Discovers Cisco devices
Discovers third-party devices
TLVs are grouped into three groups, minimum, standard, and maximum. Global settings and port settings can define which group to use. Configuration of which TLVs are in the standard and maximum groups is supported.
TLV selection is supported for optional TLVs.
Support for TLV selection in transmission-Provides the ability to specify which TLVs are to be included in the outgoing frames