Core services
Multiple VLANs, inter VLAN routing, DNS, DHCP, monitoring, logging, and protected server access.
Network lab · Completed
Network.
A secure Cisco environment linking headquarters and a branch, built to be tested, broken, and repaired.
This project turns CCNA topics into a realistic network across two locations. It documents the design, configuration, verification, packet evidence, failure diagnosis, and repair process instead of showing only the final topology.
TYPENetwork engineering lab
PLATFORMCisco routing and switching
FOCUSCCNA · security · operations
DELIVERYEvidence · repository documentation
01 · The goal
Build proof of networking ability, not another list of topics studied.
The lab models two business locations with segmented users and services, dynamic routing, controlled internet access, encrypted traffic between sites, and centralized operational visibility.
Every major feature has an acceptance test. Selected configurations were intentionally broken so the project could document the symptoms, evidence, root cause, repair, and final verification.
02 · Network topology
Two sites. Segmented inside. Encrypted between.
Headquarters provides central services and visibility. The branch retains local access while learning remote routes and reaching approved resources through the encrypted tunnel.
Routed VPN path
OSPF route exchange, NAT at the edge, ACL enforcement, and encrypted traffic between sites.
Remote operations
Segmented client networks, local switching and routing, service access, monitoring, and controlled failure scenarios.
03 · Build scope
The configuration works as one system.
Each area was configured and validated individually, then tested again across VLAN, routing, service, security, and site boundaries.
Multiple VLANs
Separate user, server, management, voice, and guest traffic into intentional broadcast and security boundaries.
Inter VLAN routing
Route required traffic between VLANs while preserving clear gateways, addressing, and troubleshooting paths.
OSPF
Exchange routes dynamically between the headquarters and branch routing layers and verify neighbor and route behavior.
DHCP and DNS
Provide repeatable client addressing and name resolution across segmented networks and routed site boundaries.
NAT
Translate internal addressing at the internet edge and verify expected outbound traffic without exposing internal networks.
ACL segmentation
Allow required business flows and block unnecessary access between users, servers, guests, and management networks.
Site to site VPN
Protect traffic moving between headquarters and the branch and validate the encrypted tunnel under normal and failed conditions.
Central visibility
Collect logging and monitoring data centrally so routing, security, service, and device events can be correlated.
Packet validation
Use Wireshark captures and deliberately broken configurations to prove behavior, isolate faults, and document each repair.
04 · Validation workflow
Design, build, break, prove.
The project documentation records the working configuration, controlled failures, diagnosis process, repairs, and final verification.
- 01
Design
Defined the two site topology, VLAN plan, addressing, trust boundaries, services, and acceptance tests before configuring devices.
- 02
Build
Configured switching, routing, OSPF, DHCP, DNS, NAT, ACLs, VPN connectivity, and central operational visibility.
- 03
Break and diagnose
Introduced controlled faults across Layer 2, Layer 3, services, security policy, and the VPN, then diagnosed each issue from evidence.
- 04
Validate and document
Captured working configurations, route and neighbor output, logs, packet traces, failure reports, repair notes, and repository documentation.
Verified evidence
Every claim points to something an employer can inspect.
The case study includes the topology, sanitized configurations, verification commands, central logs, Wireshark captures, fault records, repair notes, and repository documentation.
Validation summary
The network was built, tested under normal conditions, exposed to controlled faults, repaired from evidence, and verified after each change. The supporting notes preserve the reasoning behind the final configuration.
The larger takeaway