14.9.11 Packet Tracer - — Layer 2 Vlan Security

By default, switches are trusting. And trust, in security, is a vulnerability.

On any port that should not be a trunk (i.e., all end-user ports), explicitly turn off trunking:

In the world of networking, we often talk about firewalls, ACLs, and encryption. But what happens if an attacker simply unplugs a legitimate user’s laptop and plugs in a rogue device? What if they spoof a VLAN or launch a MAC flood?

Move the native VLAN to an unused, "dead-end" VLAN.

Layer 2 security is invisible when done right. But when it's missing, the whole network crumbles. What other Layer 2 attacks worry you most—CDP/LLDP recon, STP manipulation, or ARP poisoning? Drop a comment below.