Question 890
During a planned campus-network change at an engineering school in Copenhagen, operators discover that a downstream switch reports an unsupported SFP and its routed neighbor never becomes reachable. The design must preserve lab networks and WLAN testing. Which post-change observation is the strongest acceptance evidence?
Explanation
Correct Answer
This observation tests the Physical/link layer diagnosis and interface counters requirement at an engineering school in Copenhagen. The expected result is that the repaired interface has stable link state, no continuing physical errors and expected packet forwarding. The necessary correction is to check physical state, optics/cabling, speed/duplex and error counters before investigating routing or application-layer faults; a saved configuration alone would not prove it is working. In this case, the observed fault is that a downstream switch reports an unsupported SFP and its routed neighbor never becomes reachable.
Incorrect Answers
At an engineering school in Copenhagen, this measures a different network requirement, WLAN association, authentication and DHCP triage. The case describes that a downstream switch reports an unsupported SFP and its routed neighbor never becomes reachable, so accepting this result would leave the primary fault without direct verification.
At an engineering school in Copenhagen, this would verify Layer-three routing and application path troubleshooting, not the failure reported in this scenario. The requested closure criterion instead concerns Physical/link layer diagnosis and interface counters: the repaired interface has stable link state, no continuing physical errors and expected packet forwarding.
At an engineering school in Copenhagen, the observation may be useful for a separate Wireless radio bands and channel availability test, but it does not establish that a downstream switch reports an unsupported SFP and its routed neighbor never becomes reachable has been resolved. The relevant check is the Physical/link layer diagnosis and interface counters outcome.