Fifteen questions on modules 1 and 2, using the two-floor office from the lab: PC1 (192.168.10.11) and PC2 (192.168.20.11) on SW1 ports Gi1/0/1 and Gi1/0/3, PC3 (192.168.10.12) on SW2 Gi1/0/1, trunks R1–SW1 and SW1–SW2 carrying VLANs 10, 20 and native VLAN 99, and R1 routing with subinterfaces Gi0/0.10 (192.168.10.1) and Gi0/0.20 (192.168.20.1). If you get one wrong, the explanation names the lesson to go back to.
1. PC1 sends an ARP broadcast. Which of the other PCs receive it?
2. Port Gi1/0/5 has switchport access vlan 10 and switchport voice vlan 40, with a PC plugged into an IP phone. How does the switch receive the PC's frames?
3. A port on a new Cisco Catalyst switch has no configuration at all. Which VLAN is it in?
4. PC1 sends a frame to PC3. What does SW1 do to it before sending it across the SW1–SW2 trunk?
5. SW1's operational trunk uses native VLAN 99 and allows VLANs 10,20,99. Native tagging is confirmed disabled, and all three VLANs are active and forwarding. Which VLAN's data frames cross untagged?
6. Another vendor's switch port is 'untagged in VLAN 10, tagged in VLAN 40'. What is the Cisco equivalent?
7. SW1 logs '%CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on GigabitEthernet1/0/23 (99), with SW2 GigabitEthernet1/0/24 (1).' What is the fix?
8. In the lab the native VLAN is 99 and no access port is in it. Can PC2 (VLAN 20) use a double-tagged frame to reach VLAN 10?
9. You add subinterface Gi0/0.30 on R1 as the gateway 192.168.30.1/24 for a new VLAN 30. Which command ties the subinterface to VLAN 30?
10. The office replaces R1 with a multilayer switch. interface Vlan10 and interface Vlan20 have their gateway addresses and no shutdown. Which global command makes the switch route between them?
11. On SW1, show vlan brief lists Gi1/0/1 under VLAN 10 and Gi1/0/3 under VLAN 20, but Gi1/0/23 and Gi1/0/24 appear nowhere. Is something wrong?
12. On SW2, show interfaces trunk lists VLAN 20 under 'Vlans allowed on trunk' but not under 'Vlans allowed and active in management domain'. What is the likely cause?
13. PC2 sends an ICMP reply with initial TTL 128. PC1 receives it with TTL 127. What does this indicate about the reply path?
14. PC1 can reach PC2 but not PC3. On SW1, show interfaces trunk shows 'Gi1/0/23 20,99' under 'Vlans allowed on trunk'. Which command fixes it without breaking anything else?
15. Guests in VLAN 20 get 169.254.x.x addresses while employees get proper addresses. The DHCP server is on another subnet and has a VLAN 20 pool. What should you check?