STP ROOT BATTLE_
Elect the root bridge before you run out of lives. Read the bridge priorities and MAC addresses and call the winner, then name the port roles and states. Lowest bridge ID wins — and when priority ties, the lowest MAC takes it. CCNA spanning tree, drilled fast.
★ SPANNING TREE CHEAT NOTES
[ THE RULES ]
Root election: lowest Bridge ID wins = priority first, then lowest MAC. Default priority 32768, set in steps of 4096 (lower 12 bits = the VLAN / extended system ID). Port roles: the root bridge has only designated ports; each non-root switch picks one root port (lowest cost to root); every link has one designated port; the leftover is blocking (alternate). 802.1D states: Blocking → Listening → Learning → Forwarding. RSTP (802.1w): Discarding, Learning, Forwarding.
Why it's tested. Spanning tree shows up across switching questions — root election, port roles, and the convergence states. The election rule is dead simple once it's automatic: compare priority, and only fall back to the MAC on a tie.
How to play. Pick Endless to survive on three lives, or Daily 10 for a fixed set that's the same for everyone today. Tap an answer or press 1-4. Every answer shows a one-line explanation.