Project: design a small office network end to end

Goal and requirements

The goal is to act as the network engineer for a fictional office of 20 staff and deliver a design that someone else could build and support. Write a short brief first, for example:

• 20 staff with laptops, 10 desk phones, two printers and a small NAS (network-attached storage).
• Wi-Fi for staff and for visitors, with visitors kept away from company devices.
• Secure remote access for staff working from home.
• Budget-conscious, easy to manage, and able to grow to 40 people.

Tools: Cisco Packet Tracer or GNS3 for the build, a drawing tool for diagrams, and a spreadsheet for the IP plan. No real customer data is needed.

Design

Explain each choice: why /24 leaves room to grow (check with the subnet calculator), why voice gets QoS (quality of service), how many PoE (Power over Ethernet) watts the phones and access points need (try the PoE calculator), and which traffic the firewall allows between VLANs.

Build plan

1. Build the switch: VLANs, access ports, trunk to the router, port security and disabled unused ports.
2. Build the router or firewall: subinterfaces, DHCP pools, NAT for internet access and inter-VLAN rules.
3. Add wireless: staff SSID on VLAN 10 with WPA3 or WPA2-Enterprise, guest SSID on VLAN 40 with client isolation.
4. Harden devices: SSH only, local and AAA (authentication, authorisation, accounting) accounts, NTP, syslog and banners.
5. Add remote access: a client VPN design, with MFA on the VPN login.
6. Plan backup: device config backups and a 3-2-1 backup plan for the NAS.

show vlan brief
show interfaces trunk
show ip interface brief
show ip dhcp binding
show ip nat translations
show access-lists
show running-config | section line vty

Deliverables and testing

• Requirements summary and assumptions.
• Logical and physical diagrams, an IP and VLAN plan, and a bill of materials with rough costs.
• The Packet Tracer file or lab configs.
• A test plan with expected and actual results: staff reach the NAS, guests cannot, phones get the voice VLAN, unused ports are shut, SSH works and Telnet does not.
• A one-page handover guide covering how to add a user, reset a port and restore a config.

Presenting it in your CV and portfolio

Describe outcomes, not just tools. For example: "Designed and built a segmented five-VLAN network for a simulated 20-user office, including guest isolation, voice QoS and a 15-case test plan." Put the diagrams, IP plan and test results in a public repository or PDF (without real names or addresses), and be ready to explain in an interview why you chose each VLAN and rule. This project maps well to CCNA topics and many coursework briefs.