In the vast web of interconnected devices that make up the internet and private networks, network routing is the crucial process that ensures data packets travel from their source to the correct destination. Without efficient routing, communication across networks would be chaotic or even impossible. This article explains what network routing is, how it works, the types of routing, and why it is essential for modern digital communication.
What is routing?
Routing is the process of selecting the best path for data packets to travel across a network from their source to their destination. This essential function in computer networks enables efficient and reliable communication by determining the most appropriate network path for data to follow. Routing involves making decisions about which path to take to reach a destination network or device based on various criteria, including distance, cost, and traffic conditions.
Importance of Network routing
Routing is the process of path selection in any network. A computer network is made of many machines, called nodes, and paths or links that connect those nodes. Communication between two nodes in an interconnected network can take place through many different paths. Routing is the process of selecting the best path using some predetermined rules.
How Routing Works
Data moves along any network in the form of data packets. Each data packet has a header that contains information about the packet’s intended destination. As a packet travels to its destination, several routers might route it multiple times. Routers perform this process millions of times each second with millions of packets.
When a data packet arrives, the router first looks up its address in a routing table. This is similar to a passenger consulting a bus timetable to find the best bus route to their destination. Then the router forwards or moves the packet onward to the next point in the network.
For example, when you visit a website from a computer in your office network, data packets first go to the office network router. The router looks up the header packet and determines the packet destination. It then looks up its internal table and forwards the packet—either to the next router or to another device, such as a printer—within the network itself.
Types of Network Routing
Routing is typically of 3 types, each serving its purpose and offering different functionalities.
Static routing
A network administrator manually configures and selects network routes using static tables in static routing. Static routing proves useful when the network’s configuration or characteristics are expected to remain constant.
A disadvantage of this static routing strategy is network congestion. Static routing sometimes hampers network performance and reduces the adaptability and flexibility of networks. Even when managers set up fallback pathways for connection failures, the network remains less responsive to changes.
Dynamic Routing
Dynamic Routing is another type of routing in which routing is an autonomous procedure without any human intervention. Network devices transmit packets using various shortest-path algorithms and pre-determined metrics. Modern networks mostly prefer this type of routing because it offers greater flexibility and more versatile functionality.
The biggest advantage of dynamic routing is that it adapts to changing network conditions, including traffic volume, bandwidth, and network failure.
Default Routing
Default Routing is a routing technique in which a router is configured to transmit packets to a default route that is, a gateway or next-hop device if no specific path is defined or found. It is commonly used when the network has a single exit point. The IP Router has the following address as the default route: 0.0.0.0/0.
Common Routing Protocols Explained
A routing protocol defines rules that routers use to identify and forward packets along a network path. We group routing protocols into two main categories: interior gateway protocols and exterior gateway protocols.
Interior gateway protocols work best within an autonomous system—a network administratively controlled by a single organization. External gateway protocols better manage the transfer of information between two autonomous systems.
Interior gateway protocols
Interior Gateway Protocols are designed for routing within a single autonomous system (AS)—a network under a single administrative control, like a corporate network or a university campus.
The following are some examples of interior gateway protocols.
Routing Information Protocol(RIP): RIP is one of the oldest routing protocols. The Routing Information Protocol (RIP) relies on hop counts to determine the shortest path between networks.
Open Shortest Path First (OSPF): OSPF is a dynamic routing protocol that uses a link-state database to construct a complete picture of the network and determine the shortest path for data packets.
Enhanced Interior Gateway Routing Protocol (EIGRP): EIGRP is a Cisco proprietary protocol. It uses an algorithm to determine the best path for data and can adapt quickly to changes in network conditions.
External gateway protocols
Exterior Gateway Protocols handle routing between different autonomous systems—essentially between different organizations’ networks. The internet itself consists of thousands of interconnected autonomous systems, making EGPs crucial for global connectivity.
Border Gateway Protocol (BGP): BGP is the protocol that makes the internet work. It handles routing between autonomous systems (networks) and is responsible for making sure your data gets where it needs to go on the vast global network.
Network Routing Algorithms
Software programs called routing algorithms implement different routing protocols. They assign a cost number to each link using various network metrics. Each router calculates these costs and forwards the data packet to the next best link with the lowest cost.
The following are some example algorithms.
Distance Vector Routing algorithm
The Distance Vector Routing algorithm requires all routers to periodically update each other about the best path information they have found. Each router sends information about the current assessment of the total cost to all known destinations. The Distance Vector Routing algorithm uses the Bellman-Ford algorithm to assign a cost number to each link between nodes.
Eventually, every router in the network discovers the best path information for all possible destinations.
Link State Routing algorithm
The Link State Routing algorithm uses a graphical map of the network to determine the least-cost path from each node to every other node. Routers share information about their immediate connections, allowing each router to build a complete network map. This algorithm is used in protocols like OSPF and IS-IS.
What are the Advantages of Network Routing?
- Overall, routing works in various ways. It’s important to understand the requirements and choose the method that best fits our specific needs. Many prefer automated routing because algorithms handle packet routing efficiently. However, manually configurable routing allows us to control the network more precisely.
- Routing is a highly scalable operation for transmitting data that is, in a large-scale enterprise network it becomes crucial to manage information related to all the nodes that may be sharing sensitive and confidential information regarding the organization.
- Load Balancing is also one of the crucial aspects taken care of by routing data packets off the routes that are generally busy as sending data through those routes will only put our data at risk of getting lost.
What are the Disadvantages of Network Routing?
- Restricted Bandwidth: A primary drawback of routers is that their bandwidth may be restricted. This indicates that a network’s capacity to transfer data is constrained, which may result in delays and slowdowns. For instance, a single router may be used to connect several devices to the internet in a residential environment, which can lead to congestion and sluggish internet rates. This may be especially troublesome in a corporate context since it can cause delays and slowdowns in crucial company activities.
- Exposure to Cyberattack Risks: The susceptibility of routers to attackers is another drawback. Because routers serve as network gateways and can grant access to sensitive data, hackers frequently target them. Furthermore, networks may be susceptible to hacking efforts if routers lack the security measures needed to fend off intrusions. For instance, a hacker may use a router’s vulnerability to enter a network and take private data.
- Network Overhead: Additional network overhead brought on by dynamic router interactions reduces the amount of bandwidth that can be used for user data. This may cause the network to lag and perform worse overall.
- Requirements for Configuration: In order for routers to function correctly, they must first undergo a significant amount of configuration. This might take a lot of time and require specialized expertise, which some smaller organizations can find difficult to do.
Modern Routing Concepts
Cloud routing involves dynamically managing connections between virtual cloud networks. As cloud computing environments grow, efficient cloud routing ensures seamless communication between distributed resources and services. Routers play a crucial role in managing traffic flow and directing data packets within packet switching networks, ensuring that network packets reach their intended destinations through intermediary devices.
Conclusion
Network routing is a foundational concept that powers every digital interaction in our connected world. Whether it’s routing inside a small home network or across vast global data centers, it ensures that information arrives at the right place, at the right time, through the most efficient path possible. As networks continue to evolve with technologies like SD-WAN and 5G, routing will remain a central pillar of modern communication.
