Match each Cisco IOS interface line status or counter symptom on the left to its most likely physical or data link layer cause on the right.
- Interface status is 'GigabitEthernet0/1 is down, line protocol is down'Layer 1 physical link failure, such as a disconnected cable, missing transceiver, or remote end power loss.
- Interface status is 'FastEthernet0/1 is up, line protocol is down'Layer 2 operational issue, such as an encapsulation mismatch, keepalive failure, or port security violation.
- Interface status is 'GigabitEthernet0/2 is up, line protocol is up' with rapidly incrementing late collisionsDuplex mismatch resulting from hardcoding full duplex on one side while the remote end operates in half duplex.
- Interface status is 'FastEthernet0/2 is administratively down, line protocol is down'The interface configuration contains the default 'shutdown' command.
Cevap
The interface conditions match as follows: 'down/down' indicates a Layer 1 physical carrier loss; 'up/down' indicates a Layer 2 framing or encapsulation failure; 'late collisions' on an operational interface indicate a duplex mismatch; and 'administratively down' indicates the port is disabled by configuration.
In Cisco IOS interface diagnostics: physical layer carrier loss generates 'down/down'; data-link framing or keepalive failures generate 'up/down'; duplex mismatches generate late collisions; and administrative shutdown settings generate 'administratively down'.
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Anahtar Kavram
Cisco IOS interface line status, protocol states, and error counter interpretation