He walked off. The switches hummed.
Packet Tracer’s simulation mode revealed the truth: red packets dropping at the trunk port, rejected like a bouncer checking an expired ID.
interface gigabitEthernet 0/1 switchport mode trunk switchport trunk allowed vlan 10,20,30 Same on S2’s G0/1 and S3’s G0/2. 3.3.12 packet tracer - vlan configuration.pka
Professor Lasky walked by, glanced at the screen, and said only: “Three VLANs today. Three hundred in the real world. The logic doesn’t change.”
“I need a trunk,” Alex whispered.
“Wait,” Alex frowned. “That’s good. But why can’t PC1 ping PC3?”
But Professor Lasky had hidden a trap. The instructions, step 7: “Verify that PC3 cannot ping PC5.” Alex did. It couldn’t. Good. He walked off
“Perfect isolation,” Alex said, closing Packet Tracer. “Almost as good as my weekend plans.”