Routing & Switching Chapter 1: Fundamentals of WANs and IP Routing

Fundamentals of WANs and IP Routing

• A basic local area network (LAN) can be connected using a hub, which is an antiquated device that connects wires together.
• A switch can break up collision domains, resulting in a lot less network congestion.
• A router creates an internetwork and breaks up broadcast domains.

Internetworking Devices

• A router breaks up both broadcast and collision domains for every LAN interface.
• A switch only breaks up collision domains.
• A network with all these internetwork devices in place would have routers, switches, and other devices working together.

How IP Addressing Helps IP Routing?

• IP addressing helps IP routing by providing a unique address for each device on the network.
• This allows devices to communicate with each other and for routers to route traffic efficiently.

Protocols that Help IP Routing

• Domain Name System (DNS) resolves hostnames to IP addresses.
• Address Resolution Protocol (ARP) resolves IP addresses to Ethernet (MAC) addresses.

Physical Components of Network

• WLAN devices connect wireless devices to the network.
• Access Points (APs) allow wireless devices to connect to a wired network and extend a collision domain from a switch.
• WLAN Controllers manage access points in medium to large quantities.
• Firewalls monitor and control incoming and outgoing network traffic based on predetermined security rules.

OSI Model

• OSI model is a layered architecture that consists of seven layers.
• Each layer defines a set of functions that take part in data communication.
• The seven layers are:
  • Application Layer (Layer 7): provides an interface for users to interact with applications or networking services.
  • Presentation Layer (Layer 6): defines a standard format to the data.
  • Session Layer (Layer 5): establishes, maintains, and terminates sessions.
  • Transport Layer (Layer 4): provides data delivery mechanism between applications in the network.
  • Network Layer (Layer 3): provides logical addressing and path determination (routing).
  • Data Link Layer (Layer 2): provides reliable transit of data across a physical link.
  • Physical Layer (Layer 1): defines the electrical, mechanical, and functional specifications for communication between network devices.

Transport Layer

• The Transport Layer provides data delivery mechanism between applications in the network.
• The major functions described at the Transport Layer are:
  • Identifying service using port numbers.
  • Multiplexing and de-multiplexing.
  • Segmentation and reassembling.
  • Error correction.
  • Flow control.
• The protocols that work at the Transport Layer are TCP and UDP.

Network Layer

• The Network Layer provides logical addressing and path determination (routing).
• The protocols that work at the Network Layer are routed protocols (IP, IPX, AppleTalk) and routing protocols (RIP, OSPF).
• Routing protocols perform path determination (routing).

Data Link Layer

• The Data Link Layer has two sublayers: MAC (Media Access Control) and LLC (Logical Link Control).
• MAC provides reliable transit of data across a physical link and error detection using CRC (Cyclic Redundancy Check).
• LLC provides communication with the Network Layer.

Physical Layer

• The Physical Layer defines the electrical, mechanical, and functional specifications for communication between network devices.
• The functions described at the Physical Layer are:
  • Encoding/decoding: converting binary data into signals based on the type of media.
  • Electrical, mechanical, and functional specifications for communication between devices.

This quiz covers the basics of WANs and IP routing, including network fundamentals, hubs, and switches. It explores how devices are connected and segmented in a local area network.