← 1-6 Ethernet Switching

Switchboard

Pick a moment. Guess what the switch does. Send the frame.

Browser Lab · Layer 2 only

The switch and its MAC table

HOST A
02:00:00:00:00:0A
Ready
HOST B
02:00:00:00:00:0B
Ready
HOST C
02:00:00:00:00:0C
Ready
NO CABLE
LINK DOWN
Excluded
MISSION L2-04Power
PORT 1
PORT 2
PORT 3
PORT 4
1 Learn source
2 Look up destination
3 Take action
MAC address table
MAC addressPortAge left
No frame on the wire yet.

1. Pick a moment

2. What will the switch do?

The switch has no map yet. Choose what you think it will do, then send Host A's first frame to Host B.

Edit the frame

Nerd tip A switch learns only from the source MAC. It never learns a destination by looking it up. Linux bridges show the same table with bridge fdb show br br0.