Lecture CCNA Exploration 4.0 (Kỳ 3) - Chapter 1: LAN Design

This chapter describe how a hierarchical network supports the voice, and data needs of a small- or medium-sized business. Describe the functions of each of the three levels of the hierarchical network design model, the principles of hierarchical network design, and the concept of a converged network. Provide examples of how voice and video over IP affect network design,...
Nội dung trích xuất từ tài liệu:
Lecture CCNA Exploration 4.0 (Kỳ 3) - Chapter 1: LAN Design Chapter 1: LAN Design CCNA Exploration 4.0 1 Overview Học viện mạng Bach Khoa - Website: www.bkacad.com 2 Introduction to life cycle of a network Học viện mạng Bach Khoa - Website: www.bkacad.com 3 Enterprise Network Học viện mạng Bach Khoa - Website: www.bkacad.com 4 Small Campus Network Design Học viện mạng Bach Khoa - Website: www.bkacad.com 5 Medium Campus Network Design Học viện mạng Bach Khoa - Website: www.bkacad.com 6 Multilayer-Switched Campus Backbone Design Học viện mạng Bach Khoa - Website: www.bkacad.com 7 Large-Scale Multilayer-Switched Campus Backbone Học viện mạng Bach Khoa - Website: www.bkacad.com 8 Principles of Design 1. Redundant Network Design Topologies 2. Hierarchical Network Design 3. Modular Network Design 4. Secure Network Design Topologies Học viện mạng Bach Khoa - Website: www.bkacad.com 9 Enterprise Campus Design Methodology Học viện mạng Bach Khoa - Website: www.bkacad.com 10 Hierarchical Network Model Học viện mạng Bach Khoa - Website: www.bkacad.com 11 Switched LANs, access layer overview 1. The access layer provides users in workgroups access to the network. 2. The distribution layer provides policy- based connectivity. 3. The core layer ( backbone ) provides optimal transport between sites. Học viện mạng Bach Khoa - Website: www.bkacad.com 12 Enterprise Campus Infrastructure Học viện mạng Bach Khoa - Website: www.bkacad.com 13 Access layer switches • An access layer switch should provide this functionality with low cost and high port density. – Catalyst 2950 series – Catalyst 2960 series – Catalyst 2960 series – Catalyst Express 500 series – Catalyst Express 520 series Catalyst Express 500 series Catalyst Express 520 series Học viện mạng Bach Khoa - Website: www.bkacad.com 14 Access layer switches • Access layer switches operate at Layer 2 of the OSI model and provide services such as VLAN membership. • Access layer functions also include MAC layer filtering and microsegmentation. – MAC layer filtering allows switches to direct frames only to the switch port that is connected to the destination device. – The switch creates small Layer 2 segments called microsegments. The collision domain can be as small as two devices Học viện mạng Bach Khoa - Website: www.bkacad.com 15 Enterprise Campus Infrastructure Học viện mạng Bach Khoa - Website: www.bkacad.com 16 Distribution Layer • The purpose of this layer is to provide a boundary definition in which packet manipulation can take place. • Networks are segmented into broadcast domains by this layer. • Policies can be applied and access control lists can filter packets. • The distribution layer also prevents problems from affecting the core layer. • Switches in this layer operate at Layer 2 and Layer 3. • The distribution layer includes several functions such as the following: – Aggregation of the wiring closet connections – Broadcast/multicast domain definition – Virtual LAN (VLAN) routing – Any media transitions that need to occur – Security Học viện mạng Bach Khoa - Website: www.bkacad.com 17 Distribution layer switches 6500 4500 • Distribution layer switches are the aggregation points for multiple access layer switches. • The switch must be able to accommodate the total amount of traffic from the access layer devices. • The distribution layer combines VLAN traffic and is a focal point for policy decisions about traffic flow. • For these reasons distribution layer switches operate at both Layer 2 and Layer 3. • The following Cisco switches are suitable for the distribution layer: – Catalyst 3550/3560 series – Catalyst 4500 series – Catalyst 6500 series Học viện mạng Bach Khoa - Website: www.bkacad.com 18 Enterprise Campus Infrastructure Học viện mạng Bach Khoa - Website: www.bkacad.com 19 Core Layer • The core layer is a high-speed switching backbone. • If they do not have an associated router module, an external router is used for the Layer 3 function. • This layer of the network design should not perform any packet manipulation. • Packet manipulation, such as access list filtering, would slow down the switching of packets. • Providing a core infrastructure with redundant alternate paths gives stability to the network in the event of a single device failure. Học viện mạng Bach Khoa - Website: www.bkacad.com 20