VPN, or Virtual Private Network, is a technology that allows you to create a secure and encrypted connection over a less secure network, such as the internet. There are several types of VPNs, each with its own characteristics and use cases. Here are some common types: Remote Access VPN: This type of VPN is used … Read more

TTL Mechanism

TTL mechanism prevents packets from circulating endlessly and ensures that they either reach their destination or are dropped after a predetermined number of hops. It helps maintain network efficiency and prevents potential loops in the routing process. Initial TTL Setting:The packet leaves the source client with an initial TTL value.As it encounters the first router, … Read more

Router on a stick (ROAS)

Almost all networks in the world use Virtual Local Area Networks nowadays. In our lesson about VLANs we have learned a general rule of thumb that is: This means that if we have nodes connected in different VLANs, they most probably are part of different subnets. If we take the topology shown in Figure 1 for example, … Read more

VXLAN (Virtual Extensible LAN) and EVPN (Ethernet Virtual Private

VXLAN (Virtual Extensible LAN) and EVPN (Ethernet Virtual Private Network) are technologies used in networking to address challenges associated with large-scale, multi-tenancy data center environments. FortiGate, a product of Fortinet, is a next-generation firewall and security appliance that also offers networking capabilities. Let’s break down VXLAN and EVPN individually and then discuss how FortiGate incorporates … Read more

Troubleshooting the vPC Split-Brain Scenario

When faced with a vPC split-brain scenario, swift and methodical troubleshooting is crucial to minimize downtime and restore network integrity.Here are the steps I followed to isolate and resolve the issue: 1.Confirm Split-Brain: Verify if a vPC split-brain condition indeed exists. Check both vPC peer switches for discrepancies in their operational status.2.Analyze Logs: Dive into … Read more

VXLAN (Virtual Extensible LAN)

VXLAN (Virtual Extensible LAN) is a network virtualization technology that extends Layer 2 segments over a Layer 3 network infrastructure. It is commonly used in data center environments to facilitate network segmentation and overlay networks. VXLAN Multi-Site is an extension of VXLAN that allows for the extension of virtualized network segments across multiple data center … Read more

Private VLAN (PVLAN) on Cisco IOS Switch

Many network students believe private VLANs are very complex when they see this for the first time. I’m going to break it down and explain to you how it works.The private VLAN always has one primary VLAN. Within the primary VLAN, you will find the promiscuous port. In my picture above, you can see a router … Read more

Number System

The number system or the numeral system is the system of naming or representing numbers. We know that a number is a mathematical value that helps to count or measure objects and it helps in performing various mathematical calculations. There are different types of number systems in Maths like decimal number system, binary number system, octal … Read more


. Divides on single broadcast domain into multiple broadcast domains. VLANs provide a way to group devices within a LAN VLAN divides into a single broadcast domain into multiple broadcast domains. VLAN – Benefits VLAN Types 2. Data VLAN ( User VLAN) 3. Voice VLAN 4. Management VLAN VLAN Ranges Range Use Propagated 0, 4095 … Read more

Cisco Packet Tracer Download

Cisco Packet Tracer allows students to practice networking concepts in a simulated environment without needing expensive hardware or risking damage to networks. The tool also allows students to experiment with network topologies and configurations and observe the effects of their changes in real-time. Download

Network Address Translation Lab

Introduction The purpose of this exercise is to learn how to configure NAT for a campus network. We will be setting up NAT on the border router so that the campus private IPv4 address space (172.2X.0.0/16) will be NATed so that devices using that private address space can reach the public Internet. Setting up NAT … Read more


Introduction The purpose of this exercise is to create separate VLANs for different groups of users in each building. In a later exercise we will configure the core router so that each VLAN is using a different IP subnet. This lab is a continuation from the Spanning Tree exercise and the lab setup is identical: … Read more


Lab Objective The focus of this lab is to understand basic VLAN, VTP, DTP and STP implementation and configuration in Cisco IOS Catalyst switches. Lab Topology The lab network topology is illustrated below: Topology Task 1 Enable and configure VTP on the switches illustrated in the topology as follows: DLS1 DLS1(config)#vtp domain SWITCH Changing VTP … Read more