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In this article I describe the Two tier network topology for ccna. I can give you an overview of Two tier network topology for ccna, along with examples. A two tier network topology, also known as a two-layer network architecture, is a network design that consists of two distinct layers or tiers of networking devices. This topology typically includes access layer switches/devices at the lower tier and distribution/core layer switches/devices at the upper tier. Each layer serves specific functions and has distinct characteristics. Let’s delve into the characteristics of each tier with examples:
Access Layer:
The access layer, also known as the edge layer, is the lower tier of the two tier network architecture. It serves as the entry point for end-user devices, providing connectivity to the network infrastructure. The primary characteristics of the access layer include:
Device Connectivity:
Access layer switches connect end-user devices such as computers, laptops, printers, IP phones, and wireless access points (APs) to the network. These devices typically use Ethernet or Wi-Fi connections to access network resources and services.
Port Density:
Access layer switches often have a high port density to accommodate numerous end-user devices connected to the network. They may feature Fast Ethernet (10/100 Mbps) or Gigabit Ethernet (10/100/1000 Mbps) ports, depending on the bandwidth requirements of connected devices.
User Access Control:
Access layer switches enforce access control policies to restrict network access based on user identities, device types, or security profiles. They support features such as port security, MAC address filtering, 802.1X authentication, and VLAN (Virtual LAN) segmentation to ensure secure and controlled access to network resources.
PoE Support:
Access layer switches may support Power over Ethernet (PoE) to provide electrical power to connected devices such as IP phones, wireless APs, and surveillance cameras. PoE eliminates the need for separate power adapters and electrical outlets, simplifying device deployment and installation.
Traffic Segmentation:
Access layer switches use VLANs to segment network traffic into separate broadcast domains, isolating traffic from different user groups or departments. VLANs enhance network security, optimize bandwidth utilization, and facilitate network management by grouping devices logically.
Example:
In a corporate network environment, access layer switches are deployed in wiring closets or IDF (Intermediate Distribution Frame) rooms on each floor or in each department. These switches connect end-user devices in cubicles, offices, or conference rooms to the corporate LAN/WAN infrastructure.
Distribution/Core Layer:
The distribution/core layer, also known as the aggregation layer, is the upper tier of the two tier network architecture. It serves as the backbone of the network, aggregating traffic from access layer switches and providing connectivity to other parts of the network or external networks. The primary characteristics of the distribution/core layer include:
Aggregation and Interconnection:
Distribution/core layer switches aggregate traffic from multiple access layer switches and interconnect different parts of the network, such as campus buildings, data center racks, or remote branches. They provide high-speed connectivity to ensure efficient data exchange between network segments.
Routing and Packet Forwarding:
Distribution/core layer switches perform routing functions to forward traffic between VLANs or subnets within the network. They use routing protocols such as OSPF (Open Shortest Path First) or EIGRP (Enhanced Interior Gateway Routing Protocol) to calculate optimal paths and make forwarding decisions based on network topology and routing metrics.
Redundancy and High Availability:
Distribution/core layer switches implement redundancy mechanisms such as link aggregation (EtherChannel) and Spanning Tree Protocol (STP) to provide fault tolerance and high availability. Redundant links and switches ensure network resilience and minimize downtime in case of link failures or switch malfunctions.
Quality of Service (QoS):
Distribution/core layer switches support QoS mechanisms to prioritize network traffic and ensure optimal performance for critical applications. They classify, prioritize, and queue traffic based on criteria such as application type, traffic volume, or service level agreements (SLAs), ensuring that latency-sensitive or mission-critical applications receive preferential treatment.
Security and Access Control Lists (ACLs):
Distribution/core layer switches enforce security policies and access control lists (ACLs) to filter and control traffic entering or exiting the network. They inspect packets, apply access control rules, and enforce security policies to protect against unauthorized access, denial-of-service (DoS) attacks, or malware propagation.
Scalability and Growth:
Distribution/core layer switches are designed for scalability and future growth, with modular chassis, high port densities, and support for advanced features and protocols. They accommodate increasing network traffic, new services, and expanding network infrastructure without requiring extensive redesign or reconfiguration.
Example:
In a campus network environment, distribution/core layer switches are deployed in main equipment rooms or MDF (Main Distribution Frame) locations. These switches aggregate traffic from access layer switches in different buildings or departments, provide connectivity to the campus backbone, and connect to external networks such as the internet or data center networks.
Conclusion for Two tier network topology for ccna:
A two tier network topology architecture provides a scalable, efficient, and manageable network design suitable for small to medium-sized organizations or campus environments. The access layer serves as the entry point for end-user devices, providing connectivity and access control, while the distribution/core layer aggregates traffic, performs routing functions, and ensures network scalability and resilience.
Understanding the characteristics and functions of each tier is essential for designing, deploying, and managing a robust and reliable network infrastructure. I hope you found this article helpful related to Two tier network topology for ccna. You may drop a comment below or contact us for any query or suggestions related to the contents of this website.
