Packet Basics Lab
Trace a ping across a simple LAN and identify MAC/IP boundaries.
Objectives
- Build a two-PC + switch topology in Packet Tracer
- Assign IPv4 addresses on the same subnet
- Verify L2 switching with show mac address-table
- Observe ARP and ICMP with simulation mode or debug
Topology
PC-A ── Switch0 ── PC-B (same VLAN, same /24 subnet). No router required.
Prerequisites
- Basic Packet Tracer navigation
- Week 1 lessons on Ethernet, MAC, and ARP
Instructions
Step 1
Build the topology
Add two PCs and one 2960 switch. Connect both PCs to the switch with copper straight-through cables. Confirm link lights are green.
Step 2
Address the hosts
Assign static IPv4 addresses on the same network. Example: PC-A 192.168.1.10/24, PC-B 192.168.1.20/24, both with mask 255.255.255.0.
PC> ipconfig 192.168.1.10 255.255.255.0 PC> ipconfig 192.168.1.20 255.255.255.0
Step 3
Ping and trace
From PC-A, ping PC-B. Enable simulation mode and watch the ARP request/reply, then ICMP echo request/reply. Note: ARP stays on the LAN; IP addresses identify end hosts.
PC> ping 192.168.1.20
Step 4
Inspect the switch CAM table
On Switch0, confirm both MAC addresses are learned on the correct access ports.
Switch# show mac address-table Switch# show mac address-table dynamic
Verification checklist
- Ping succeeds between both PCs
- show mac address-table lists one entry per PC on the correct port
- Simulation shows broadcast ARP, then unicast ICMP
Troubleshooting
Ping fails with request timeout
Check IP/mask on both PCs, cable types (straight-through to switch), and that interfaces are up.
MAC table empty
Generate traffic with a ping first; verify cables and that you are on the switch CLI.