Open the lab
[ YOUR LAB FILE ]
Download the starting topology, then work through the lesson in SwitchLab.
- Save the .swlab file without renaming its extension.
- Open SwitchLab. Import and export controls currently require a desktop-width window. On a smaller screen, Tools → Fit brings the topology into view.
- Select Import Sandbox (folder icon), choose the downloaded file, and confirm the device and cable counts below.
- Select a device, then choose Open device on desktop or its name in the bottom bar on smaller screens. Select CLI for switches/routers or Desktop → Terminal for PCs. Enter
enableonly when the prompt ends in >. - Follow this page beside the simulator. Use a free account to export your work. Reimport the original download to restart; export any work you want to keep first.
Prerequisites
- Complete the Ethernet fundamentals lessons.
- For the routed troubleshooting lessons, recognize connected and static routes.
Topology
3 devices · 2 links
Scenario
A small service desk was allocated 192.168.50.64/26. PC2 already follows the plan; PC1 was given an address from the preceding subnet. Commission PC1 at the first usable address.
Objectives
- Derive or verify IPv4 host and gateway settings against the approved subnet plan.
- Prove the intended local and routed paths after correcting configuration.
CCNA blueprint
200-301 v1.1 objectives — this lab covers the following specific skills, not every subtopic in the domain.
- 1.6 — Configure and verify IPv4 addressing and subnetting.
Starting information
- The approved subnet is 192.168.50.64/26. PC2 keeps 192.168.50.66; PC1 must use the first usable host address.
- Both PCs connect to the same VLAN 1 switch. There is no router and no default gateway. The table below records the starter values, not the requested final plan.
| Host | IPv4 address | Mask | Gateway |
|---|---|---|---|
| PC1 | 192.168.50.10 | 255.255.255.192 | None |
| PC2 | 192.168.50.66 | 255.255.255.192 | None |
| Device / port | Device / port |
|---|---|
| PC1 / eth0 | SW1 / g0/1 |
| PC2 / eth0 | SW1 / g0/2 |
Tasks
- Calculate the network address, broadcast address, usable host range and dotted-decimal mask for the allocated /26.
- Run
ipconfig /allon both PCs and attempt PC1 → 192.168.50.66. Explain why sharing a switch does not put their configured IP addresses into the same subnet. - On PC1 use
netsh ip set 192.168.50.65 255.255.255.192to apply the first usable address without a gateway. - Verify the new host configuration, ping PC2 from PC1, then ping 192.168.50.65 from PC2. Export and reload your completed network.
Useful commands
show interfaces status
copy running-config startup-configProgressive hints
Hint 1
Calculate the subnet boundary before changing an address. A gateway is used only for a destination outside the host subnet.
Hint 2
Compare all three settings—address, mask and gateway. A successful ping alone may not reveal an overly broad mask.
Hint 3
Use the first usable address for each requested gateway; for PC repairs, apply netsh ip set with the exact approved address, mask and gateway.
Verification
- The final addressing matches the approved plan exactly.
- All paths listed in the tasks succeed in both directions.
- The completed export retains the repaired addressing after reload.
Solution / walkthrough
Show Solution
Use enable only from a > prompt; if already at #, begin with configure terminal.
PC1
A /26 has blocks of 64 addresses: this allocation runs from .64 through .127, with usable hosts .65–.126. No gateway is needed for same-subnet traffic.
netsh ip set 192.168.50.65 255.255.255.192Run every verification check above after the changes. A saved configuration alone does not prove packet delivery.