if a network has added new equipment, we need to be done on other equipment related operations, so as to make the whole network, so it is very troublesome for large networks, but if you are using a cisco router, so all this is not a problem, its unique discovery protocols can easily help you see the newly added network equipment, without other additional operations.
a, each running CDP router discovery protocol will exchange agreement with their neighbors information, network in case of need, CDP information exchange can be showed in the console connected to the local router, on any a router, type the command: show CDP neighbors, can be shown with information about the router directly connected devices.Most of
1, about the CDP maintenance must be conducted in privileged mode, use the Enable command to enter privileged mode, only in this mode, to view the information of neighbor equipment, in the input command, only need to input nei three characters, and then press the Tab key, the system will automatically filling the back of the payment, and don't need to lose all, convenient English not very good user.
2, this command can reflect the equipment label ID, local interface, connection time, function, platform, port label, VTP domain name management, information such as the local Vlan, working mode, if the information can't meet demand, so can also behind this command to add a detail parameters, so, you can display more detailed information.
2, by default, CDP discovery protocol is enabled globally, but some of the old equipment may need to manually start the discovery protocols, we through the CDP only enabled the RUN command, at the same time also found support in interface mode using CDP agreement, if you want to enable this feature, you need to enter the interface configuration mode, and then use CDP enable enable CDP in the interface, the interface on the CDP discovery protocol is not enabled by default.
three, use this command to obtain CDP for notifications and found the data frame transmission of information, this information includes the frequency of the holding time, CDP group sending, interface encapsulation of time as well as the management and the agreement of the blocks and so on, these information for the follow-up maintenance, especially the CDP performance optimization, are of great reference value.
four, although the CDP to automatically discover new the increasing number of network devices, but it is a double-edged sword, on the one hand, enhances the flexibility of the network, on the other hand also created a lot of network security hidden danger, if illegal invaders if breached a router, you can through the CDP devices attached to the discovery protocol to get to know and its relevant information, it's the next step to carry out attacks provides very important information, for safety we can disable CDP this particular device discovery protocol, using the no CDP the run command.
through the introduction of the above, I believe your CDP on cisco router discovery protocol had certain understanding.