Cisco
300-615 · Question #284
What does "line protocol is down" indicate in this output?
The correct answer is C. The physical interface fails to receive keep-alive messages. "Ethernet1/1 is up, line protocol is down" means the physical PHY sees link but the datalink (line- protocol) isn't coming up, often because the interface isn't receiving the required keep-alive or link pulses from its peer.
Network
Question
What does "line protocol is down" indicate in this output?
Exhibits
Options
- AThe Cisco Discovery Protocol failed to start.
- BThe OSPF instance experiences an adjacency issue.
- CThe physical interface fails to receive keep-alive messages.
- DThe default gateway is unavailable.
How the community answered
(17 responses)- A6% (1)
- B12% (2)
- C82% (14)
Explanation
"Ethernet1/1 is up, line protocol is down" means the physical PHY sees link but the datalink (line- protocol) isn't coming up, often because the interface isn't receiving the required keep-alive or link pulses from its peer.
Topics
#line protocol#keepalive#interface status#L2 troubleshooting
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