Standby Redundancy Topology with HSRP Protocol

🔍 Overview

This project demonstrates a fault-tolerant and highly available Layer 3 network using the HSRP (Hot Standby Router Protocol). It implements redundant multilayer switches, VLAN segmentation, DHCP services, and EtherChannel aggregation to simulate a professional enterprise-grade topology.

🎯 Objectives

• Ensure gateway redundancy using HSRP.
• Provide IP addressing via DHCP to all VLANs.
• Use EtherChannel (LACP) for link aggregation.
• Segment traffic using multiple VLANs.
• Enhance manageability and logging using Syslog, NTP, and ACLs.

🧹 Topology Components

• 2 Multilayer Switches (core1, core2)
• 3 Access Switches
• 4 VLANs (10, 20, 30, 40)
• 2 DHCP Servers
• Multiple PCs distributed across VLANs
• Syslog & NTP server
• Redundant links with EtherChannel

🔐 VLAN & HSRP Configuration

🔧 Services

• DHCP Server (192.168.10.50)
  • Provides IPs to all VLANs via ip helper-address on core switches.
• Syslog Server
  • Collects logs from both core switches.
• NTP Server
  • Synchronizes time across all network devices.

🔒 Access Control List (ACL)

• Traffic from VLAN 20 to VLAN 10 is restricted to improve security.
• ACLs are applied in inbound direction on core switches’ VLAN interfaces.

Example:

access-list 101 deny ip 192.168.20.0 0.0.0.255 192.168.10.0 0.0.0.255
access-list 101 permit ip any any
interface vlan20
 ip access-group 101 in

🥺 Redundancy Testing

To simulate failover:

• Disable the active switch interface (e.g. shutdown vlan10 on core1).
• Verify HSRP failover occurs and standby router becomes active.
• Use show standby to observe state transitions.

🏁 Conclusion

This topology offers a resilient Layer 3 switching infrastructure. It ensures network availability during device failures and provides dynamic IP allocation, segmented traffic, and enhanced logging for troubleshooting and monitoring.