HP ProCurve 2650 User Manual

10-16
Configuring for Network Management Applications
CDP
Figure 10-6. Example of Outgoing CDP Packet Operation
Incoming CDP Packets
When a CDP-enabled Switches 2650 and 6108 receives a CDP packet from
another CDP device, it enters that device’s data in the CDP Neighbors table,
along with the port number where the data was received (and does not forward
the packet). The switch also periodically purges the table of any entries that
have expired. (The hold time for any data entry in the switch’s CDP Neighbors
table is configured in the device transmitting the CDP packet, and cannot be
controlled in the switch receiving the packet.) A Switch 2650 or 6108 reviews
the list of CDP neighbor entries every three seconds, and purges any expired
entries.
Non-CDP devices such as some hubs and other devices that do not have CDP
capability are transparent to CDP operation. (Other hubs are CDP-aware, but
still forward CDP packets as if they were transparent to CDP operation. See
“CDP-Capable Hubs” on page 10-29.) However, an intervening CDP-aware
device that is CDP-disabled is not transparent. For example, in figure 10-7, the
Switch "A"
HP Switches with
CDP Running and
Forwarding CDP
Packets to Down-
stream Devices
Switch "B"
CDP-Aware
Switch with
CDP Running
Switch "C"
CDP-Aware
Switch with
CDP Disabled
Router "Y"
With CDP
Disabled or
Nonexistent
Device "Z"
Hub or Other
Non-CDP
Device
Router "X"
With CDP
Running
Accepts, but does not forward CDP
packets describing Switch "A". Also
transmits CDP packets describing itself
(Switch "B") out all ports.
Drops CDP packets describing Switch "A".
Also does not transmit any CDP packets
describing itself (Router "Y").
Forwards CDP packets from Switch "A" out
all ports (except the port receiving the
packets from "A") without any awareness
of CDP operation.
Drops CDP packets describing Switch
"A". Also, does not transmit any CDP
packets describing itself (Switch "C").
Accepts, but does not forward CDP
packets from Switch "A". Also transmits
CDP packets describing itself (Router "X")
out all ports.
!Software.book Page 16 Thursday, October 10, 2002 6:10 PM

HP ProCurve 2650 Specifications

General

Switching Capacity	13.6 Gbps
Forwarding Rate	10.1 Mpps
Layer	2
Jumbo Frame Support	Yes
Form Factor	Rack-mountable
VLAN Support	Yes
Layer 3 Routing	No
PoE Support	No
Fanless	No
Altitude	Up to 3, 000 meters
Management	CLI, SNMP
Operating Temperature	0°C to 50°C
Storage Temperature	-40°C to 70°C
Humidity	15% to 95% non-condensing