Emma Lavina / Projects / Network simulation

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Multi-site network simulation

SAÉ 201
Juin 2025 IUT Blois — BUT R&T S2 Solo

Design and deployment of a complete three-site enterprise network in Cisco Packet Tracer. The project covered inter-site routing with OSPF, VLAN segmentation per department, dual-stack IPv4/IPv6 addressing, NAT for internet access, and ACLs for traffic filtering. Deliverable: a working topology + a full technical report.

Cisco IOS OSPF VLANs IPv4/IPv6 NAT ACLs Packet Tracer
Packet Tracer file — available on request

Screenshots

Packet Tracer topology

Full three-site topology

OSPF routing table

OSPF routing table — show ip route

VLAN config

VLAN segmentation per department

Ping tests

End-to-end connectivity tests

What I worked on

RT1
Equipment configuration and VLAN segmentation I configured all the Cisco routers and switches from scratch — interfaces, trunks, access ports. The VLAN setup was probably the part I spent the most time on: four VLANs per site (LAN, DMZ, Admin, Wi-Fi) to isolate departments and control what talks to what. Getting inter-VLAN routing right on the layer-3 switches took a few iterations.
RT2
OSPF routing and NAT Inter-site connectivity runs on OSPF — one area per site, area 0 as the backbone. Seeing the routing tables converge correctly after configuring the adjacencies was satisfying. NAT/PAT handles internet access for the private LANs, and I set up port forwarding to expose the DMZ web servers externally without opening up the whole network.
RT3
ACLs and access control Traffic filtering is where the security logic lives. I wrote extended ACLs to block inter-VLAN flows that shouldn't exist, protect the DMZ servers from unauthorized internal access, and restrict SSH management to the Admin VLAN only. Writing ACLs forces you to think about what needs to communicate and why — it's easy to be too permissive without realizing it.
RT4
Dual-stack addressing and network services The addressing plan covers both IPv4 (private RFC 1918 + public ranges) and IPv6, running in parallel across all three sites. On top of that: DNS with zone delegations between sites, DHCP for end-user devices, and HTTP/FTP servers in the DMZ. Building the addressing table before touching any device saved a lot of time later.
RT6
Testing methodology and technical report I validated the topology progressively: physical connectivity first, then VLANs, then routing, then services, then ACLs. Catching issues layer by layer rather than debugging everything at once makes things much more manageable. The technical report covers architecture choices, the addressing tables, and the full OSPF and ACL configurations with justifications.