Implemented VLAN Segmentation and Inter-VLAN Routing Setup

Layer 3 Switch: A multilayer switch can perform both switching and routing functions. It is ‘Layer 3 aware’, meaning it can operate at the network layer of the OSI model. You can assign IP addresses to its interfaces, similar to how you would with a router. Virtual interfaces can be created for each VLAN, and each can be assigned an IP address. You can also configure routes on a multilayer switch, just like a router. These switches are commonly used for inter-VLAN routing, allowing communication between different VLANs without requiring an external router.   SVIs (Switch Virtual Interfaces) are virtual interfaces on a multilayer switch to which you can assign IP addresses. Each PC should be configured to use the SVI (not the router) as its gateway address. To send traffic between different subnets/VLANs, PCs send their traffic to the switch, and the switch routes the traffic between VLANs. To enable an SVI (Switch Virtual Interface) on a switch, the following conditions must be met: 1.       The VLAN must exist on the switch. 2.       The switch must have at least one access port in the VLAN in an up/up state, and/or one trunk port that allows the VLAN that is in an up/up state. 3.       The VLAN must not be shutdown (the shutdown command can disable a VLAN). 4.       The SVI must not be shutdown (SVIs are disabled by default). Syntax: Interface vlan <Vlan ID> Ip address <IP Address> <subnet mask> IP routing This command enables the layer 3 functions in the L3 switch Int gi0/0 No switchport This configures the interface as a ‘routed port’, which means it's a Layer 3 port and not a Layer 2 switchport.   #Ntworking #switch #Coreswitch #Tagging #Vlan

VRF (virtual routing and forwarding ):- 👉VRF is a technique used to separate and manage multiple routing tables on a single physical router . 👉Each VRF instance has its own routing table ,which is isolated from other VRF 's on the same router . Features of VRF :- 👉Seperate routing table : Each VRF has its own routing table , which contains routes specific to that VRF. 👉 Multiple instances: Multiple VRF instances can be configured on a single physical router. 👉VRF commonly used in MPLS VPN deployments to separate customer traffic and maintain confidentiality. 👉 Before configure the ip address we should assign VRF. Benefits :- 👉Improved security 👉 Increased flexibility 👉Better Scalability VRF configuration command:- Router (config)# ip VRF (VRF name ) Router (config)# exit Router (config)# int f0/1 Router(config)# ip VRF forwarding (VRF name ) 👉Eigrp vrf command:- Router(config)# Eigrp( vrf name ) Router(config)# address-family ipv4 Router(config)# address -family ipv4 VRF (VRF name ) autonomous system number Router (config)# Network (network id) Router (config)# Exit 👉This is for VRF (virtual routing and forwarding ) explanation .

🚀🚀Spanning Tree Protocol (STP) is a Layer 2 network protocol that prevents network loops by creating a single, active path between any two endpoints, selectively blocking redundant paths. It operates by exchanging Bridge Protocol Data Unit (BPDU) messages between switches to detect loops and build a loop-free topology. Cisco switches support various STP versions, including STP (802.1D), RSTP (802.1w), MSTP, and PVST+, which offer different features and convergence speeds. Why STP is Important🚀 Prevents Network Loops:🚀 Without STP, redundant links in a switched network can create loops, leading to broadcast storms that flood the network with traffic and cause instability. Ensures a Stable Topology:🚀 STP ensures a single active forwarding path, providing network stability and reliable communication. Key STP Concepts🚀🚀 Root Bridge:🚀 The switch with the lowest Bridge ID (priority + MAC address) that becomes the central point for the spanning tree. Root Port: On a non-root switch, the port with the lowest-cost path to the root bridge. Designated Port:🚀 On a segment, the port that is the designated forwarding port for that segment. Blocked Port:🚀 Redundant paths are placed in a blocking state to prevent loops, even though they are physically connected. BPDU (Bridge Protocol Data Unit): Special messages exchanged between switches to elect the root bridge and determine port roles. Configuring STP on a Cisco Switch Access the Switch CLI: 🚀Log in to the Cisco switch's console. Enter Global Configuration Mode: From Privileged EXEC mode, type configure terminal. Select STP Mode: 🚀Choose the desired STP mode using commands like spanning-tree mode mst or spanning-tree mode rapid-pvst. Enable STP on Ports: For specific interfaces, you can use features like spanning-tree portfast to allow direct connection to end devices and immediately forward traffic.

🔹 Layer 2 Protocols: Problem Solvers in Action 🔹 In networking, we often focus on flashy technologies at higher layers. But the real unsung heroes are the Layer 2 protocols—quietly solving critical problems behind the scenes. Here are a few examples: ✅ Ethernet – The backbone of LANs. It solved the problem of connecting multiple devices in a simple, standardized way. ✅ Spanning Tree Protocol (STP) – Prevents network loops. Without STP, a single misconfigured cable could bring down an entire network with a broadcast storm. ✅ VLAN (802.1Q) – Solves the problem of segmentation. Instead of buying multiple switches, VLANs allow us to logically divide one switch into many secure networks. ✅ Link Aggregation (LACP) – Solves bandwidth and redundancy issues by bundling multiple links into one logical connection. ✅ ARP (Address Resolution Protocol) – Bridges the gap between IP addresses (Layer 3) and MAC addresses (Layer 2), ensuring devices can actually communicate. 💡 Takeaway: Whenever you face a network issue at Layer 2—loops, congestion, or segmentation—chances are one of these protocols has already been designed to solve it. The key is knowing when and how to apply them. #ARP #VLAN #trunk #linkaggregation #ethernet

✴️What is EtherChannel?✴️ EtherChannel is a Cisco technology that bundles multiple physical links into one logical link to increase bandwidth and provide redundancy. It can combine up to 8 physical Ethernet links into one logical link, which helps with: ✅️ Load balancing ✅️ Fault tolerance ✅️ Simplified configuration 🔷️ EtherChannel supports different protocols: ✅️ PAgP (Port Aggregation Protocol) – Cisco proprietary. ✅️ LACP (Link Aggregation Control Protocol) – IEEE standard (802.3ad). ✅️ Static (On mode) – No negotiation protocol. ✳️How to Configure EtherChannel?✳️ ✅️Example: Switch-1 (Using LACP - Active mode) Switch(config)# interface fastethernet 0/23 Switch(config-if)# channel-group 2 mode active Switch(config)# interface fastethernet 0/24 Switch(config-if)# channel-group 2 mode active Switch(config)# interface port-channel 2 Switch(config-if)# switchport mode trunk Switch(config-if)# switchport trunk native VLAN 99 Switch(config-if)# switchport trunk allowed VLAN 2,3,99 ✅️Example: Switch-2 (Using Static mode - On) Switch(config)# interface fastethernet 0/23 Switch(config-if)# channel-group 5 mode on Switch(config)# interface fastethernet 0/24 Switch(config-if)# channel-group 5 mode on Switch(config)# interface port-channel 5 Switch(config-if)# switchport mode trunk Switch(config-if)# switchport trunk native VLAN 99 ✳️Important Notes:✳️ ✅️ Both switches should use the same mode (either active-active for LACP, or on-on for static). ✅️ VLAN settings on both sides must match. ✅️ You must configure the same EtherChannel group number on both interfaces that are bundled. ✅️ Port settings (speed, duplex, VLAN) should be identical on all bundled interfaces.

🚀 A quick win for faster STP convergence- Backbone Fast! Ever heard of Backbone Fast? It’s a Cisco proprietary enhancement to Spanning Tree Protocol that can cut recovery time by up to 20 seconds during indirect link failures. 🔍 How it works: When a switch receives an inferior BPDU, it suspects a topology issue. Instead of waiting for the usual 20-second max_age timer, it sends a Root Link Query (RLQ) upstream to verify the root bridge’s status. If confirmed, it accelerates port transitions, restoring connectivity faster. ✅ Key benefits: - Faster recovery from indirect failures - Smarter topology verification - Seamless integration with other STP enhancements like UplinkFast and PortFast 📌 Pro tip: Backbone Fast must be enabled on all switches in your network to be effective. If you're optimizing your Layer 2 design, this is one feature worth implementing. Let’s make networks more resilient—one protocol tweak at a time. Picture Credits : Respective Owner Picture source: Social Media #Cisco #STP #BackboneFast #NetworkEngineering #ITInfrastructure #TechTips

When your mission-critical systems depend on reliable Ethernet connectivity, you can't afford to compromise. The RRS4228 28-port 10Gigabit/Gigabit managed switch delivers the redundancy and resilience needed for demanding industrial, transportation, and other challenging environments. This switch features comprehensive layer 2 redundancy with STP, RSTP, MSTP, and ERPS, as well as layer 3 redundancy through VRRP. This combination ensures seamless failover and network resilience, keeping your operations running smoothly and uninterrupted. Additionally, the RRS4228 is equipped with advanced layer 3 routing capabilities, supporting both static and dynamic routing protocols, including RIP, OSPF, and multicast routing with PIM-SM, PIM-DM. With a wide voltage range and extreme temperature tolerance, this switch is ideal for deployment in virtually any environment. Flexible management options are available through web UI, CLI, and remote access, providing you with the control and visibility needed to maintain your industrial Ethernet network proactively. Don't settle for anything less than exceptional performance in mission-critical Ethernet connectivity. For more information or to request a detailed specification sheet, please feel free to contact us. More details can be found at www.iethcom.com. Interested in becoming one of our channel partners? Contact us at info@iethcom.com.

🚀 Exciting news! Presenting an Enterprise Network Simulation in Cisco Packet Tracer, Powered by BenTech 📍 Originating in Tshwane and designed for global scalability. ## 📡 Exploring the Blueprint Embark on a simulation of an expandable enterprise featuring: - 6 Routers - 12 Switches - 35+ PCs - 4 Servers Each component mirrors real-world implementation: Core, Access, Server Farm, WAN Edge ## 🛣️ Understanding Routing & Redundancy Experience dynamic routing using OSPF for: - Swift convergence - Redundant pathways - Utilization of /30 WAN links for ISP-grade dependability ## 🔐 Implementing VLAN Segmentation Enhance security and performance through logical segregation: - VLAN 10: HR - VLAN 20: IT Support - VLAN 30: Admin - VLAN 40: Engineering Incorporating: - Trunk links connecting switches and routers - Department-specific access ports - Router-on-a-Stick for inter-VLAN routing - Application of ACLs to prevent unauthorized cross-VLAN traffic ## 🖥️ Deploying Server Farm Introduce enterprise services within secure subnets: - `Server0`: DHCP for dynamic IP allocation - `Server1`: FTP for file sharing across VLANs - `Server2`: Email for internal communication - `Server3`: Database as the backend for simulated applications Ensuring Security & Monitoring: - Implementing ACLs to restrict access based on VLAN/IP - Activating SNMP for real-time alerts and monitoring ## 💼 Real-World Relevance This is more than a lab setup—it's a blueprint for practical implementation.

🚀 Mastering Trunk Ports & VLAN Protocols In networking, Trunk Ports are the real backbone of VLAN communication. While access ports are tied to one VLAN, trunk ports handle multiple VLANs simultaneously — making enterprise networks scalable, efficient, and secure. 🔹 What Makes Trunk Ports Special? Carry traffic for multiple VLANs over a single physical link. Use tagging to identify which VLAN each Ethernet frame belongs to. Reduce cabling, optimize bandwidth, and keep networks well-structured. ⚡ Protocols That Make It Work: IEEE 802.1Q (Dot1Q): The current industry standard for VLAN tagging. Adds a 4-byte tag inside the Ethernet frame (only increasing the frame size to 1522 bytes, which most devices support). More efficient and widely compatible. ISL (Inter-Switch Link): Cisco’s proprietary protocol (now retired). Encapsulated the entire frame, adding 30 bytes overhead, pushing the frame size to up to 1548 bytes. Higher overhead = less efficiency, which is why Dot1Q replaced ISL in modern networks. 📌 Why This Matters: Choosing the right trunking protocol impacts performance and compatibility. Dot1Q is lighter, faster, and universally supported — making it the preferred choice for today’s VLAN-based networks. #TrunkPorts #VLAN #VLANProtocols #NetworkingBasics #CiscoNetworking #NetworkEngineering #ITInfrastructure #NetworkSecurity #Switching #DataCommunication #ComputerNetworks

Static routing is a network configuration method in which routes are manually set up by the network administrator. Unlike dynamic routing protocols, static routes do not change automatically; they remain fixed until manually modified. When configuring IP static routing, an administrator manually defines the path (next-hop IP address or exit interface) that packets should take to reach a specific destination network. Key Points of Static Routing: Manual Configuration: Routes are entered manually by the administrator. Next-Hop & Interface: Specifies the next-hop router’s IP address or the outgoing interface. Simplicity: Easy to configure on small networks. Control: Provides complete control over routing paths. Low Resource Usage: Does not consume CPU or bandwidth for routing updates like dynamic protocols. Limitation: Not scalable for large or frequently changing networks.