12-18
Configuring for Network Management Applications
CDP
Monitoring and Managing
the Switch
Non-CDP devices (that is, devices that are not capable of running CDP) are
transparent to CDP operation. However, an intervening CDP-aware device
that is CDP-disabled is not transparent. For example, in figure 12-7 (page 16),
"B", "D", and "E" are not CDP neighbors because "D" (the intervening CDP-
disabled switch) does not forward CDP packets; i.e. is not transparent t o CDP
traffic. (For the same reason, switch "E" does not have any CDP neighbors.)
Figure 12-7 (page 12-16) illustrates how multiple CDP neighbors can appear
on a single port. In this case, switch "A" has three CDP neighbors on port 1
because the intervening devices are not C DP-capable and simply forward CDP
neighbors data out all ports (except the port on which the data was received).
Configuring CDP on the Switch
On a Switch 4108GL you can:
■View the switch’s current global and per-port CDP configuration
■List the current contents of the switch’s CDP Neighbors table (that is,
view a listing of the CDP devices of which the switch is aware)
■Enable or disable CDP (Default: Enabled)
■Specify the hold time (CDP packet time-to-live) for CDP data deliv-
ered to neighboring CDP devices. For example, in CDP switch "A" you
can specify the hold time for switch "A" entries in the CDP Neighbor
tables of other CDP devices. (Default: 180 seconds)
■Specify the transmission interval for CDP packets. (Default: 60
seconds)

CLI: Viewing and Configuring CDP

CLI Commands Described in this Section
show CDP below
show CDP neighbors page 12-19
cdp clear page 12-20
[no] cdp run page 12-21
[no] cdp enable page 12-22
cdp holdtime page 12-22
cdp timer page 12-23