Cisco Discovery Protocol
(CDP) is a device-discovery protocol that runs on all
Cisco network equipment. Each bridge sends identifying
messages to a multicast address, and each bridge monitors
the messages sent by other bridges. Information in CDP
packets is used in network management software such
as CiscoWorks2000. Use the CDP page to adjust the bridge's
CDP settings.
CDP Properties
Cisco Discovery
Protocol (CDP)
Select Disabled
to disable CDP on the bridge; select Enabled
to enable CDP on the bridge. CDP is enabled by default.
Packet
Hold Time (optional)
The number of seconds other
CDP-enabled bridges should consider the CDP information
valid. If other bridges do not receive another CDP
packet from the bridge before this time elapses,
the bridge has probably gone offline. The default
value is 180. The packet hold time should always
be greater than the value in the Packets Sent Every
field.
Packets
Sent Every (optional)
The number of seconds between
each CDP packet that the bridge sends. The default
value is 60. This value should always be less than
the packet hold time.
Individual
Port Enable
Ethernet--When selected,
the bridge sends CDP packets through its Ethernet
port and monitors the Ethernet for CDP packets
from other bridges.
Radio0-802.11A--When
selected, the bridge sends CDP packets through
its internal radio port and monitors the internal
radio for CDP packets from other bridges.
Note:A MIB file is available
for use with CDP. The filename is CISCO-CDP-MIB.my,
and you can download the MIB at the following URL:
http://www.cisco.com/public/mibs/v1/CISCO-CDP-MIB-V1SMI.my
CDP
Neighbors Table
This section displays
the type of bridge that is discovered.
Specifically, it displays the following
values:
Device
ID
The configured
ID, MAC address, or serial number
of the device.
Interface
The
number and type of the local interface
protocol being used.
Hold
time
The
number of remaining seconds the
current bridge holds the CDP advertisement
from a transmitting router before
discarding it.
Capability
The
device type as listed in the CDP
Neighbors table. Possible values
are R for router, T for transparent
bridge, B for source-routing bridge,
S for switch, H for host, or I for
IGMP device. If you click the calculator
image, you see a popup with the
legend of code to capability.