14.9.11 Packet Tracer - Layer 2 Vlan Security May 2026
The four techniques in form the backbone of the Cisco Cyber Threat Defense model:
Move the native VLAN to an unused, "dead-end" VLAN. 14.9.11 packet tracer - layer 2 vlan security
By default, switches are trusting. And trust, in security, is a vulnerability. The four techniques in form the backbone of
| Threat | Mitigation | | :--- | :--- | | MAC Flooding | Port Security | | VLAN Hopping (DTP) | switchport mode access / nonegotiate | | Double Tagging | Non-default native VLAN | | Rogue DHCP | DHCP Snooping | Packet Tracer 14.9.11 is not just about passing a skills exam—it's about building an operator mindset . The best router ACL in the world is useless if an attacker can sit on your switch and sniff everything. | Threat | Mitigation | | :--- |
That’s where comes in. It’s the often-overlooked foundation of network defense.
interface g0/1 switchport mode trunk switchport nonegotiate If a port is for a user, it should be an access port, period. Don't let devices negotiate their way into privilege. Step 3: Changing the Native VLAN (Double Tagging Defense) The Threat: In a double-tagging attack, the attacker sends a frame with two 802.1Q tags. The first tag (native VLAN) is stripped off by the first switch. The second tag (say, VLAN 10) is then visible to the next switch, potentially letting the attacker hop into a restricted VLAN.