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Explore the fundamentals of campus LANs, covering basic LAN topologies, the evolution from shared to switched networks, and the differences between LAN switching and routing. Learn about large-scale LAN design considerations and practical examples of campus networks.
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Introduce campus LANs Review basic LAN topologies LAN Switching: evolution from shared LANs LAN Switching vs Routing Large-scale (Campus) Lan design (Part I)
Local area constrained to a fixed geographical area Uses LAN technologies – Ethernet/Fast/Gigabit, Token Ring, FDDI, ATM Switching and routing technologies Large-scale (Campus) LAN
Basic LAN topologies • Bus • RingFDDI • Star • All are prone to scalability problems
Evolution from shared to switched networks • Factors stressing capabilities of traditional (shared) LANS: • Faster CPUs • Faster Operating Systems • Network-intensive applications
Benefits of switching • Bandwidth (not shared) • VLANs • Security
Routers use Layer 3 information to make routing decisions (routing tables) and choose the “optimal” path Routers use routing protocols (e.g. OSPF, BGP) to exchange updates/routing info Routers filter broadcasts and multicasts, switches don’t – can create broadcast storm Routers create separate broadcast domains Switches don’t have network (host) addresses, routers do. Routers modify destination’s physical (not network) address Routers
Layer 2 - STP (Spanning Tree Protocol IEEE 802.1D (newer protocols include RSTP and MSTP) Reliability (Fault-Tolerance) Mechanisms
Reliability (Fault-Tolerance) Mechanisms • Layer 3 – VRRP and HSRP A typical LAN
Reliability (Fault-Tolerance) Mechanisms • Layer 3 – VRRP and HSRP HSRP addressing