After a scheduled GTK rekey on a municipal classroom SSID, unicast browsing still works but broadcast instructional video to students freezes. Which frame-exchange problem best explains that symptom?
Select an answer to reveal the explanation.
Short Explanation
Unicast is a private hallway chat; broadcast video is the PA system locked with the group key. If GTK rekey goes sideways, kids still browse one-to-one but the shared stream dies. Check the group handshake, not the pairwise tunnel.
Full Explanation
After association, pairwise keys protect unicast while the Group Temporal Key protects broadcast and multicast. Failures in the group key handshake or GTK rekey leave STAs unable to decrypt group-addressed frames even when unicast still works. Classroom broadcast video is a classic symptom of GTK problems and should drive capture focus to EAPOL group-key messages and rekey timing rather than pairwise-only analysis.