14.9.11 Packet Tracer - Layer 2 Vlan Security 〈1080p〉

S1(config)# interface g0/2 S1(config-if)# switchport mode access S1(config-if)# switchport access vlan 10 S1(config-if)# spanning-tree portfast S1(config-if)# spanning-tree bpduguard enable

If a port is for a user, it should be an access port, period. Don't let devices negotiate their way into privilege. 14.9.11 packet tracer - layer 2 vlan security

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. The first tag (native VLAN) is stripped off

For the Management PC to reach all devices, the router (R1) must be configured with a new subinterface for VLAN 20. The critical security layer is added here: Standard/Extended ACLs The critical security layer is added here: Standard/Extended

These are not just exam objectives; they are daily tasks for network administrators protecting enterprise infrastructures. Whether you are preparing for the CCNA (200-301) or securing a small office network, the principles demonstrated in form the backbone of resilient, hardened switched networks.