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Day 25 69Sending CDPv2 advertisements is enabledS1#show cdp interfaceFastEthernet0/1 is up, line protocol is upEncapsulation ARPASending CDP packets every 60 secondsHoldtime is 180 secondsFastEthernet0/2 is down, line protocol is downEncapsulation ARPASending CDP packets every 60 secondsHoldtime is 180 seconds!!Output is same for interface Fa0/3 through Gi0/1!GigabitEthernet0/2 is down, line protocol is downEncapsulation ARPASending CDP packets every 60 secondsHoldtime is 180 secondsS1#The show cdp neighbors detail output displays CDP messages that contain the following use-ful information:■■■■■■Device ID: Typically the hostnameEntry address(es): Network and data-link addressesPlatform: The model and OS level running in the deviceCapabilities: Information on what type of device it is (for instance, a router or a switch)Interface: The interface on the router or switch issuing the show cdp command with whichthe neighbor was discoveredPort ID: Text that identifies the port used by the neighboring device to send CDP messagesto the local deviceAlso notice in the show cdp interface command that every interface on the switch is sending CDPmessages every 60 seconds. CDP is enabled by default and, thus, creates a security issue becauseCDP messages can be intercepted and network information discovered. CDP can easily be disabledboth globally for the entire device (no cdp run) or individually by interface (no cdp enable).