‘’Have you tried turning it on and off again?’’ This is the most efficient solution for any technical troubleshooting. Primarily if you’ve used a router at least once to connect to your home or office Wi-Fi network. Although they are complex, routers are not alien technology. But maybe it would have been better if they were.
Perhaps we wouldn’t need to turn them off and on when something’s wrong. But they still work wonders for the stability and reliability of the Internet. More specifically, they are an important component in network routing.
Routing works by choosing the best path the data needs to take across a network when traveling from one device to another. Routing decisions are very important for ensuring a reliable Internet connection. This is why routing makes use of specific protocols that can send data to its destination as quickly and efficiently as possible.
Today, we are going to crack open that plastic box named router and examine how network routing is done. Moreover, we’ll discuss the importance of a router and how routing tables add to the grander scheme of routing.
What is network routing?
In the simplest terms, routing is the process of choosing the fastest or shortest path between two points. This is done to avoid any unnecessary complication or disruption.
When it comes to IP networks specifically, routing is how information, content, and other data travel around the Internet. IP routing relies on knowing the destination address of the data it is going to direct. And here IP addresses prove their importance again.
Once the destination is discovered, the router will use routing algorithms to determine the shortest path from one network to another until the data finally reaches its destination.
How does network routing work?
To understand the process more easily, we can look at the steps data takes on its route from the source device to its destination. You can view this journey as a hop from one network to another. Let’s see how this is done.
Step 1 – The source device sends the data to a router
Devices will ”attach” IP addresses to data packets just like your order has your delivery address written on the package. Routers use these IPs to figure out the best routes the data should take.
Step 2 – The router receives the data and reads the IP address
When a router receives an incoming data packet, it will read the IP address the packet contains. The router will then compare the address to internal routing tables. This will help it decide which path the data should take to quickly arrive at its destination.
Step 3 – The router forwards the data
The first router will not always be able to send the data directly to its destination. Instead, it will use the information provided in the routing table to work out the closest network the data can hop to in order to get closer and closer to its destination.
Step 4 – The process repeats
When the data hops to another network, a new router will decide the best next hop for it to take. This is done because data rarely gets from its source straight to its destination. That’s not an issue, however. Thanks to routing protocols, the data is still able to hop from network to network as fast and efficiently as possible.
Step 5 – When the data finally reaches a router in the same network as the destination address, the router can send it directly to the target device or server.
What is a routing table?
As we mentioned before, routers will use routing tables to figure out the best destination the data should take. But what are those tables?
Well, a routing table is a record, or a list, within every router. It informs which path the data should take. Each such table contains a list of destinations. These destinations are IP address prefixes to which the data can be forwarded.
The follow-up is quite easy to understand. As the data reaches a router, that router will read the IP address attached to it. The router will then check the IP against its list of destinations – the routing table. Finally, it works out the best route for the data.
While it sounds straightforward, you should know that a router must check its routing tables millions of times each second. And that’s for handling an average amount of traffic. So imagine how it goes for larger amounts of traffic.
Are there different types of routing tables?
There are always different types of the same thing in the world of networking, so the answer is yes. Routing tables come into two types: static and dynamic.
Static routing tables are set by a network administrator. They do not change unless the administrator updates them. They are mostly used by smaller networks, as they will become inefficient at larger scales.
Dynamic routing tables, by contrast, can update themselves automatically. They predict the shortest and fastest routes the data can take by using dynamic routing protocols. Dynamic routing takes in information about network conditions.
To put it simply, dynamic routing tables work like a GPS app. Just as the GPS detects traffic jams and recalculates a better route, dynamic routing algorithms will choose the best possible path while avoiding disconnected networks or high-traffic routers.
This makes it obvious that dynamic routing tables are best suited for medium to large networks. After all, you wouldn’t want to manually update the tables with tons of prefixes and information.
But what is a router, specifically?
We all know those plastic boxes that have bleeping lights and allow us to connect to the Internet with our smartphones. But have you ever wondered how the router works its magic? And why do we mention it so often when we talk about network routing? Let’s discuss this.
A router is a piece of hardware that forms a connection between networks or subnetworks. For that, the router is essential for distributing data across the Internet.
Routers are responsible for two main things – managing traffic flow and connecting multiple devices.
Firstly, a router is the Internet’s mail sorting office. It handles traffic flows between two or more networks that exchange information. It reads the destination IP address attached to the incoming data and forwards them in the right direction.
Secondly, a router lets multiple devices use a single Internet connection. This means you can connect your laptop, smartphone, and other devices to the same router and use that single connection to access the Internet.
Therefore, it’s the job of the router to know where to send the data. It needs to both figure out the best possible route and redirect the information to the right device within its network.
What is a routing protocol?
A routing protocol, also known as a routing policy, is a type of network protocol. This one allows connected routers to exchange routing tables. Routing protocols can improve efficiency because they can sort the information contained within routing tables.
In short, a routing protocol specifies how routers communicate with each other to distribute information. It works by using specific software and routing algorithms.
What are the main routing protocols?
Routing protocols ease router communication and improve network stability. Because networks themselves are complex layers that make up the Internet, different routing protocols were established.
There are three most important routing protocols, namely:
- Border Gateway Protocol (BGP) – This is the main postal service of the Internet. It is the BGP that processes the data and picks the fastest and most efficient route the data can take. Often, this route means jumping from one autonomous system to another until the destination is reached. BGP usually works with autonomous systems (AS) and can be secured via RPKI.
- Routing Information Protocol (RIP) – This is an intradomain routing protocol based on the hop count (the number of routers the data has to go through). It helps small to medium-scale networks.
- Open Shortest Path First Protocol (OSPF) – Another intradomain protocol. It usually handles traffic moving around within a larger AS network like a single enterprise’s network. OSPF is considered a better alternative to Routing Information Protocol (RIP).
By now we must be on the same page about the importance of network routing. Without it, data would either get lost on its way or arrive much slower at its destination.
Sending and receiving an email or accessing a website might take only seconds. But behind the curtains, things are much more subtle and complex. For you to get to your website in mere seconds, routers must check routing tables millions of times. Routing protocols and algorithms work tirelessly to ensure the data is sent to the right place as fast as possible.
This makes the Internet not only faster but also more secure and reliable. So the next time you connect to your Wi-Fi, give your router a little credit.