An Introductory Guide to Routing & Switching

Routing and switching are the basic functions of computer networking. Routing refers to finding a path between two or more networks and switching refers to moving data from one device to another within a network.

These two concepts are the building blocks of all communications, from data to voice and video to wireless access. Businesses and organizations use routing and switching to share applications, speed access to information, enhance customer service, reduce operating costs, improve security, and enable remote connections.

What Is Routing?

Routers are devices that connect networks together. Routing uses routing protocols, which are specialized algorithms that help routers determine the best path to take data from one network to another. Standard routing protocols include the Border Gateway Protocol (BGP) and the Open Shortest Path First (OSPF) protocol.

What Is Switching?

Switches are devices that connect devices within a network. Switching uses switches to forward data from one device to another. Switches use Media Access Control (MAC) addresses to determine the destination of incoming data and forward it accordingly.

Routing vs. Switching: What’s the Difference?

When you send data like a text message, that data is broken down into tiny pieces called packets and sent over the network with the source and destination IP addresses attached. The destination is a host, which is a computer or mobile device on a network. These devices reside in a Local Area Network (LAN).

The process of sending packets from one host to another within a LAN is called switching. The process of doing that between two or more LANs is called routing.

A switch is a Layer 2 device (Data-Link Layer), while a router is a Layer 3 device (Network Layer).

Routing & Switching Strategies

A large number of decisions are made in order to get a single packet across a network. These decisions are made at each and every device, including routers, switches, and hosts.

Switching: Forwarding & Filtering Traffic

There are many types of switching: packet, circuit, multilayer, virtual circuit, wide area network (WAN), and local area network (LAN). Circuiting and virtual circuit switching almost always refer to WAN or telephone technologies. Packet switching usually concerns a router or a WAN switch.

It is highly probable that a network will be a mixture of Ethernet and 802.11 nodes. These nodes will run the Internet Protocol at Layer 3 of the Transmission Control Protocol/Internet Protocol (TCP/IP) networking model. The applications will be designed for TCP or the User Datagram Protocol (UDP).

TCP/IP Model

Switches operate at Layer 2 of the TCP/IP model or the Open System Interconnection (OSI) model. Switches forward data packets on the same network using MAC addresses. At Layer 2, the data-link layer, packets are known as Ethernet frames. Switches know where to forward Ethernet frames by keeping a table of MAC addresses.

Switches also:

• Process the Cyclical Redundancy Check (CRC)
• Filter out traffic that should not be forwarded, such as local unicast frames
• Prevent the forwarding of collisions
• Prevent the forwarding of frames with errors

Switches provide a collection of features that are part of most medium and large networks:

• Virtual local area networks (VLANs)
• Simple network management protocol (SNMP)
• Remote management
• Statistics collection
• Port mirroring
• Security such as 802.1X port-based authentication

Routing: Finding Paths

Routing is typically divided into two components: host and router. Routers handle traffic flowing between networks, but hosts make many decisions long before the packets hit the network. Most routing protocols used to find pathways to destinations are router-based, however.

Routers operate at Layer 3, the internetwork or network layer of the TCP/IP model. A router’s main function is to forward traffic to destination networks via the destination address in an IP packet. Routers know where to send data packets by maintaining a table of IP addresses.

Routers also resolve MAC addresses by using the Address Resolution Protocol (ARP). At the network layer, data is known as a packet, and Layer 2 (data-link layer) frames and MAC addresses do not exist beyond the router. This means that an Ethernet frame is destroyed once it hits a router.

When operating in a network, a router can act as the default gateway for hosts, as in most home networks. A router can be installed as an intermediate hop between other routers without any direct connectivity to hosts. Routers can also perform other tasks such as network address translation, managing access control lists, terminating virtual private networks, or quality of service.

Trends in Routing and Switching

In recent years, there have been several key trends in the field of routing and switching. Here are some of them:

• Rise of Software-Defined Networking (SDN)
  Software-defined networking allows for more flexible and scalable network management by separating the control plane, which makes decisions about where to route traffic, from the forwarding plane, which actually routes the traffic. This makes it easier to automate and manage network traffic and has led to the development of new network architectures and protocols.
• Growth of the Internet of Things (IoT)
  The expansion of connected devices has led to an increase in the amount of network traffic, putting pressure on network infrastructure. As a result, there is a growing need for efficient routing and switching technologies that can handle this increased traffic.
• Increasing Importance of Security
  As the number of cyber threats continues to grow, there is a greater emphasis on securing networks against potential attacks. This has led to the development of new security technologies and protocols, such as encryption and virtual private networks (VPNs), to protect network traffic.
• Adoption of Cloud Computing
  The growth of cloud computing has led to an increase in the use of virtualization, which allows multiple virtual machines to run on a single physical server. This requires new technologies and approaches to ensure efficient communication between virtual machines and the broader network.

What Is the Future of Routing and Switching?

The future of routing and switching is likely to be influenced by the key trends mentioned above and the use of new technologies like 5G and edge computing. Edge computing, which brings computation and data storage closer to the sources of data to improve response times and save bandwidth, will introduce new challenges related to the management of distributed networks.

The growing amount of connected devices will create a greater need for efficient routing and switching technologies. This may lead to the development of new routing protocols and algorithms as well as the use of more advanced switches and routers.

Get on the Cutting Edge of Routing & Switching at Erie Institute of Technology (EIT)

With EIT’s Network and Database Professional Program, you can meet the increasing demand for efficient switching and routing protocols and technologies. You can develop the strategies needed today to protect network security and maintain our highly interconnected communication systems.

This 21-month program will prepare you to work in the rapidly developing sector of networking and infrastructure management in IT. You’ll learn how to deploy networks, ensure the reliability and consistency of those networks, handle problems, and reduce the risk of network failure. You’ll also learn how to manage databases and make sure data is secure.

Apply online today or visit our website to learn more about our computer and design training programs in Erie.