CCNA Cisco Multi-Site Network Project 🌐

📖 About The Project

This project is a comprehensive network simulation designed to validate core CCNA (Cisco Certified Network Associate) routing and switching concepts. It simulates a realistic multi-site enterprise network connecting a Headquarters (HQ) and a remote Branch Office via a WAN link, with secure edge connectivity to an ISP.

The topology demonstrates the integration of Layer 2 switching, Layer 3 Inter-VLAN routing, dynamic routing (OSPF), and network security (ACLs & NAT).

🛠️ Technologies & Features

This lab covers topics from CCNA 1 (ITN), CCNA 2 (SRWE), and CCNA 3 (ENSA):

• VLANs & Trunks: Segmentation of Sales, Engineering, and Management traffic (802.1Q).

• Inter-VLAN Routing:

  • HQ: Layer 3 Switching using SVIs.

  • Branch: Router-on-a-Stick (ROAS) utilizing subinterfaces.

• Dynamic Routing: Single-Area OSPFv2 with default-information originate for internet route propagation.

• Network Services:

  • DHCPv4: Dynamic IP allocation for end devices.

  • NAT/PAT: Overloading a single public IP for internal private subnets.

• Security:

  • Extended ACLs: Strict traffic filtering (e.g., blocking Engineering VLAN from Management).

  • SSH: Secure remote management for network devices.

• WAN Connectivity: Serial DCE/DTE simulation between sites.

🧩 Topology Overview

Device	Role	Key Configurations
HQ-R1	Edge Router	NAT/PAT, OSPF, ACLs, Default Route to ISP.
HQ-Core-SW	L3 Core Switch	SVIs (VLAN 10, 20), DHCP Server, OSPF.
BR-R1	Branch Router	ROAS, OSPF, DHCP Server.
BR-SW1	L2 Access Switch	VLANs, Trunking, SSH Management.
ISP	Service Provider	Simulated Public Internet & DNS (8.8.8.10).

🚀 Getting Started

Prerequisites

• Cisco Packet Tracer (Version 8.0 or newer recommended) OR

• GNS3 / EVE-NG (with appropriate IOS images).

Lab Setup & Installation

This project is designed as a hands-on build exercise. To replicate this network, follow these steps:

1. Build the Topology: Open Cisco Packet Tracer and manually place the devices (3 Routers, 1 L3 Switch, 1 L2 Switch, and end devices) as described in the documentation.

2. Cabling: Connect the devices using the appropriate cable types (Serial for WAN, Copper Straight-through for LAN).

3. Manual Configuration: Access the CLI of each device and configure the interfaces, routing protocols (OSPF), and security policies.

4. End-to-End Testing: Once configured, use the verification steps below to ensure the network is functioning as intended.

🧪 Verification & Testing

To verify the network is fully functional, perform the following checks:

1. Connectivity (Ping)

• Internal: PC-Sales (HQ) should be able to ping PC-Branch (Branch).

• External: All PCs should be able to ping the ISP Server at 8.8.8.10.

2. Routing (OSPF)

Check the routing table on the HQ Core Switch:

HQ-Core-SW# show ip route
> O*E2 0.0.0.0/0 [110/1] via 10.1.1.1

3. Security (ACLs)

• Permit: VLAN 10 (Sales) -> VLAN 99 (Mgmt) = SUCCESS

• Deny: VLAN 20 (Engineering) -> VLAN 99 (Mgmt) = FAIL

4. NAT

Run a ping to the internet and check translations on the Edge Router:

HQ-R1# show ip nat translations
> Pro Inside global      Inside local       Outside local      Outside global
> icmp 209.165.200.226:1 192.168.10.10:1    8.8.8.10:1         8.8.8.10:1

💡 Key Learnings

• ACL Sequencing: Learned that permit statements for routing protocols (OSPF) and ICMP must be carefully placed before specific deny statements to prevent accidental isolation.

• NAT Troubleshooting: Resolved "Destination Host Unreachable" errors by ensuring the Edge Router had a static default route pointing to the ISP, which was then propagated via OSPF.

• Layer 3 Switching: Configured ip routing on the Core switch to offload inter-VLAN traffic from the router.

👤 Author

• LinkedIn

This project was created for educational purposes to demonstrate CCNA networking proficiency.