Network Switching Fundamentals

Switching in Network Design

• Layer 2 vs Layer 3 Switching:
  • Layer 2 switching: forwarding based on MAC addresses, occurs at the data link layer
  • Layer 3 switching: forwarding based on IP addresses, occurs at the network layer
• Switch Types:
  • Unmanaged Switches: simple, no configuration options
  • Managed Switches: configurable, support VLANs, QoS, and security features
  • PoE Switches: provide power over Ethernet to connected devices
• Switch Placement:
  • Access Layer: switches connect end-user devices to the network
  • Distribution Layer: switches aggregate traffic from access layer switches
  • Core Layer: high-speed switches connect distribution layer switches

Routing Protocols in Switching

• Routing Protocol Types:
  • Distance-Vector Protocols: RIP, measure distance based on hop count
  • Link-State Protocols: OSPF, measure distance based on bandwidth and latency
  • Hybrid Protocols: EIGRP, combine distance-vector and link-state features
• Routing Information Exchange:
  • Routing Tables: stored on each router, contain network topology information
  • Routing Updates: exchanged between routers to maintain accurate routing tables
• Protocol Characteristics:
  • Administrative Distance: ranking of routing protocols by trustworthiness
  • Convergence Time: time required for network to stabilize after topology change
  • Scalability: ability of protocol to support large, complex networks

Switching in Network Design

• Layer 2 Switching: forwarding decisions are made based on MAC addresses at the data link layer
• Layer 3 Switching: forwarding decisions are made based on IP addresses at the network layer

Switch Types and Their Characteristics

• Unmanaged Switches: simple, no configuration options, and limited functionality
• Managed Switches: configurable, support VLANs, QoS, and security features, and offer more control and management capabilities
• PoE Switches: provide power over Ethernet to connected devices, reducing the need for separate power supplies

Switch Placement in a Network

• Access Layer: switches connect end-user devices to the network, providing direct access to network resources
• Distribution Layer: switches aggregate traffic from access layer switches, acting as a connection point for multiple access layer switches
• Core Layer: high-speed switches connect distribution layer switches, forming the network backbone and providing high-speed connectivity

Routing Protocols in Switching

• Distance-Vector Protocols: measure distance based on hop count, examples include RIP
• Link-State Protocols: measure distance based on bandwidth and latency, examples include OSPF
• Hybrid Protocols: combine distance-vector and link-state features, examples include EIGRP

Routing Information Exchange and Protocol Characteristics

• Routing Tables: stored on each router, contain network topology information and are used to make forwarding decisions
• Routing Updates: exchanged between routers to maintain accurate routing tables and ensure proper network functionality
• Administrative Distance: a ranking of routing protocols by trustworthiness, used to determine which protocol to use when multiple protocols provide conflicting information
• Convergence Time: the time required for the network to stabilize after a topology change, with faster convergence times being desirable
• Scalability: the ability of a protocol to support large, complex networks, with more scalable protocols being better suited for large networks

Learn the basics of switching in network design, including layer 2 and layer 3 switching, switch types, and switch placement.