Network Topology Design

This network design features a dual-infrastructure setup using two different firewall platforms, FortiGate and Palo Alto, to provide redundancy and segmentation. The design aims to ensure high availability and robust security for a network with critical assets, likely belonging to a mid to large-sized enterprise. The network is connected to two Internet Service Providers (ISPs) labeled ISP-A and ISP-B. The connections are managed through two switches (SW-15 and SW-16) on the FortiGate side, and two other switches (SW-19 and SW-110) on the Palo Alto side. These switches act as the primary and backup points of entry for the internet traffic, ensuring that if one ISP fails, the other can still provide connectivity. This setup provides resilience and fault tolerance. On the FortiGate side, two FortiGate firewalls are deployed in a high-availability (HA) configuration. This setup means that one firewall will take over if the other fails, providing uninterrupted security services. The firewalls are connected to layer 3 switches (L3-SW7 and L3-SW13) which manage internal routing and distribution of traffic. The layer 2 switches (L2-SW13) underneath connect to end devices or servers, shown as VPCs. This segmentation allows the internal network to be divided into different VLANs (VLAN 10, 21, 22, 23), each with its IP subnet, offering isolation and traffic management according to the organization’s requirements. Similarly, on the Palo Alto side, there are two firewalls, also configured in HA. They are connected to a layer 3 switch (L3-SW8) that performs a similar role in routing and distributing traffic. VLANs (30, 31, 32, 33) are used here as well, indicating that the network is segmented based on functions or departments. This helps in controlling and securing traffic flows, as well as in implementing policies such as access control lists (ACLs) or quality of service (QoS). The purpose of this design is twofold: to provide high availability and to ensure security and segmentation across the enterprise network. By using two different firewall platforms, the design can leverage the strengths of each while maintaining a diverse security posture, which is often recommended to avoid single points of failure or uniform vulnerabilities. The VLAN segmentation helps in managing and isolating traffic, ensuring that security policies can be applied more granularly. Additionally, the HA configurations on both the FortiGate and Palo Alto sides prevent downtime during hardware failures, contributing to the network's resilience. This setup offers a scalable, secure, and resilient architecture capable of supporting a range of enterprise applications and services while maintaining strict security controls and high availability.

This design showcases a back-to-back vPC (Virtual Port Channel) topology utilizing Cisco Nexus switches. In a back-to-back vPC setup, two pairs of vPC domains are interconnected, allowing redundancy and efficient traffic distribution without the reliance on STP (Spanning Tree Protocol) to block redundant paths. The diagram includes two vPC domains: Domain 11 (Nexus 101 and Nexus 102) in the core and two access-layer vPC domains, Domain 12 (Nexus 201 and Nexus 202) and Domain 13 (Nexus 301 and Nexus 302), which are connected to the core via vPC links. Core Layer (vPC Domain 11): The core layer consists of Nexus 101 and Nexus 102, configured in vPC Domain 11. These switches are connected using a vPC peer link (Po11), composed of four 100Gb DAC cables, ensuring high-speed interconnection and synchronization. A dedicated vPC keepalive link is used to monitor the health of the vPC peers. These switches manage the interconnection between the access-layer domains, handling significant traffic loads while maintaining redundancy. Access Layers (vPC Domain 12 and Domain 13): The access layer includes two separate vPC domains, Domain 12 (Nexus 201 and Nexus 202) and Domain 13 (Nexus 301 and Nexus 302). Each domain has a vPC peer link (Po12 and Po13, respectively) with two 40Gb DAC cables, along with keepalive links for health monitoring. These switches provide connectivity for servers or endpoints in their respective domains. The back-to-back vPC design interconnects the access-layer vPC domains to the core layer using aggregated 10Gb interfaces in Port Channels Po21 and Po31, respectively. This ensures high availability and balanced traffic distribution across the uplinks. Each access-layer switch connects to both core switches, creating multiple active-active paths, eliminating any single point of failure while providing fault tolerance. Technical Benefits: High Availability: The design eliminates single points of failure with redundant paths between core and access layers. Active-Active Traffic Flow: vPC allows links to operate in an active-active state, maximizing bandwidth utilization. Reduced Convergence Times: By avoiding STP-blocked links, the design ensures faster network convergence in case of link or node failures. Scalability: The design can easily accommodate additional switches or servers by expanding the existing vPC domains or adding new ones. This design is ideal for environments requiring robust redundancy, high throughput, and minimal downtime, such as data centers or enterprise networks.

🌐 Enterprise Network Infrastructure Diagram - Complete Solution Architecture This comprehensive network topology illustrates a robust enterprise-grade infrastructure design featuring strategic placement of core networking components and protocols. Network Architecture Overview: 🔹 Core Router (ISR 4521) - Central routing hub with BGP and OSPF routing protocols 🔹 Managed Switch (Catalyst 3300-24P) - Layer 2/3 switching with VLAN segmentation and ACL implementation 🔹 Next-Gen Firewall (ASA Series) - Advanced security with HTTPS/HTTP traffic inspection and GENEVE protocol support 🔹 Application Server - Backend services and data processing 🔹 Load Balancer (F5/Cisco) - Traffic distribution and high availability Key Technologies Implemented: ✅ BGP - External routing and internet connectivity ✅ OSPF - Internal routing optimization ✅ VLAN - Network segmentation and broadcast domain isolation ✅ ACLs - Granular access control and security policies ✅ HTTPS/HTTP - Secure web traffic handling ✅ GENEVE - Network virtualization overlay protocol Benefits: High availability and redundancy Scalable network design Enhanced security posture Optimized traffic flow Centralized management Perfect reference for network architects, system engineers, and IT professionals designing enterprise-grade network solutions. #NetworkArchitecture #EnterpriseNetworking #Cisco #NetworkSecurity #LoadBalancing #VLAN #BGP #OSPF #NetworkDesign #ITInfrastructure #CyberSecurity

High Availability Network Design - A Lab-Based Implementation   Maintaining seamless connection in enterprise networks is more than only strong hardware -- it is about redundancy and smart architecture. "Hardening Network Security" by Abi Adrian, an intensive lab-packed study on how to set up and verify a robust network with FortiGate, Cisco, MikroTik devices.   Among the lab’s key findings:   Static and Dynamic OSPF Routing Configurations Link Aggregation (EtherChannel) for bandwidth and redundancy requirements Realistic failure simulation (ISP, switch, firewall) and transparent failover behavior Active-passive Internet and dual-firewall architecture,Dual firewall Complete scripts for Mikrotik, FortiGate and Cisco switches/routers   The result? A reliable topology that tolerates outages and retires nodes smoothly without affecting users—this allows to make a statement that the design fulfills its defined HA goals.   This is a good book for engineers designing lab and production netoworks that require real world resiliency.   Authored by: Abi Adrian   What part of your network would get the most use out of a setup like this? Let’s discuss!   #HighAvailability #NetworkDesign #FortiGate #Cisco #MikroTik #OSPF #LinkAggregation #Redundancy #NetworkLab #smenode #smenodelabs #smenodeacademy

Designing and implementing scalable, secure, and redundant network infrastructures is one of the most essential skills for IT professionals today. This document, “Implementing Network Infrastructure using Cisco Packet Tracer”, provides a complete step-by-step guide to building an enterprise-grade topology using Cisco’s simulation environment. From VLAN segmentation and DHCP automation to OSPF routing, NAT, ACL security, and redundancy planning, it covers the full lifecycle of a realistic company scenario (WongKito Solutions). What makes it particularly valuable is the structured methodology-starting from business requirements, moving through physical/virtual design, and concluding with verification and testing. If you’re an aspiring or practicing network engineer, this resource will sharpen both your conceptual understanding and your practical configuration skills. I highly recommend giving it a read and sharing your thoughts: Which part of the process (VLANs, OSPF, ACLs, NAT) do you find the most challenging in real-world deployments? #Cisco #Networking #PacketTracer #NetworkDesign #ITInfrastructure #smenode #smenodelabs #smenodeacademy