Cisco Packet Tracer Exercises Apr 2026

conf t interface gig0/1 switchport access vlan 10 end

Layer 2. The switch. The invisible plumbing.

R4#show ip ospf neighbor

Leo double-clicked the switch connecting R4 to the rest of the world, a humble 2960 model. He ran a quick show vlan brief . His heart stopped.

"Final Exercise: The Four-Site OSPF Nightmare." cisco packet tracer exercises

Port Gig0/1, where R4 was connected, was in VLAN 1. But the trunk port connecting this switch to the rest of the topology was allowing VLANs 10, 20, and 30. Not VLAN 1.

He held his breath. He clicked back to R4. conf t interface gig0/1 switchport access vlan 10

A small victory: the command took. But still, no hello packets. No DR election. Just a cold, digital void.

It was a silent, perfect, evil mistake. The router was shouting "Hello!" into a VLAN that vanished the moment it hit the trunk. The digital voice was being erased before it could travel a single hop. R4#show ip ospf neighbor Leo double-clicked the switch

The screen flickered. Then, a miracle: