Routing Information Protocol (RIP) is one of the first dynamic routing protocols ever developed. While it’s no longer the top choice for large, complex networks, it still has value in smaller environments and as a learning tool. Its simplicity is exactly what makes it so accessible to beginners trying to understand how data finds its way through a network.

In this article, we’ll walk you through everything you need to know about it: what it is, how it works, where it came from, and why it’s still worth knowing in today’s networking landscape.

What is the Routing Information Protocol?

Routing Information Protocol (RIP) is a distance-vector routing protocol. That means it helps routers determine the best path to reach a destination network, based not on bandwidth or speed but on the number of hops.

A hop is simply one router passing a packet to the next. So, the route with the fewest hops wins. If a destination is more than 15 hops away, this protocol won’t even try – it considers that network unreachable.

That may sound limited, but that simplicity is intentional. Routing Information Protocol was designed to be easy to implement and maintain, especially in small to mid-sized networks.

A Brief History

Routing Information Protocol has a long and interesting past. It dates back to the late 1970s when Xerox developed a routing protocol as part of its early internetworking efforts. That protocol eventually became part of the Xerox Network Systems (XNS).

When UNIX systems started gaining popularity, developers adapted the XNS version into the now-familiar Routing Information Protocol and included it in Berkeley Software Distribution (BSD) UNIX. From there, it gained recognition quickly, especially in universities and research institutions.

Eventually, Routing Information Protocol was formally documented in RFC 1058 in 1988, proving its status as one of the foundational Internet routing protocols.

How Does It Work?

Routing Information Protocol operates in a simple but effective way. Here’s the core idea:

• Each router using Routing Information Protocol maintains a routing table. This table contains all known networks and how many hops it takes to reach each one.
• Every 30 seconds, the router broadcasts its entire routing table to neighboring routers.
• When a router receives an update, it compares the incoming route with what it already knows. If the new route has fewer hops, it updates its table.
• Routing Information Protocol adds 1 hop to each route it learns through a neighbor, accounting for the distance to that router.

This process repeats continuously, so routers eventually “learn” the entire network layout.

Here’s a quick example:

• Router A knows that network X is 2 hops away.
• Router B receives that info and sees that it takes 1 hop to reach Router A.
• Router B now knows it can reach network X in 3 hops.

That’s it – basic, predictable, and easy to understand.

Versions of Routing Information Protocol

Over the years, the Routing Information Protocol has gone through several updates to adapt to new technologies and networking needs. Each version brought improvements that addressed the limitations of the one before it.

RIPv1

The original version, known as RIPv1, was introduced in the late 1980s. It supported only classful routing, which means it didn’t carry subnet information in its routing updates. This made it incompatible with more advanced subnetting techniques like Variable Length Subnet Masking (VLSM). Another drawback was that it relied on broadcast communication to send updates, which meant all devices on the local network received the data, even if they didn’t need it. Security was also a concern since RIPv1 had no built-in way to verify if the updates were coming from trusted sources.

RIPv2

RIPv2 was developed in the 1990s to overcome the limitations of RIPv1. One of the key enhancements was support for classless routing, which allowed the protocol to handle subnet masks and support VLSM. This made network design much more flexible. RIPv2 also switched from broadcast to multicast for its updates, sending data only to devices that actually needed it. Furthermore, it introduced a basic authentication feature, giving administrators the ability to control which devices could send or accept routing updates, adding a layer of security that RIPv1 lacked.

RIPng

As networks began transitioning to IPv6, the protocol needed another upgrade to remain relevant. That led to the development of RIPng, which stands for Routing Information Protocol next generation. This version was specifically designed to support IPv6 addressing, which uses a much larger address space than IPv4. The newer version retained the same core mechanisms, such as using hop count as a metric, but adapted them to work within the IPv6 protocol. RIPng also required a different transport mechanism and message format to fit IPv6 standards but remained true to Routing Information Protocol’s original goal of being lightweight and simple to implement.

Advantages of Routing Information Protocol

Despite being one of the older routing protocols, it offers several benefits:

• Easy to configure: It doesn’t require a deep understanding of networking to get started. It’s ideal for small networks or educational environments.
• Wide compatibility: As one of the earliest standardized protocols, Routing Information Protocol works on nearly all routers, even older ones.
• Low resource usage: Because of its simplicity, this protocol doesn’t demand much in terms of CPU or memory. That makes it great for older or low-power devices.
• Loop prevention: With a hop limit of 15, Routing Information Protocol prevents infinite routing loops by design. That makes the network more stable, even if it’s small.

Disadvantages

Despite its strengths, the Routing Information Protocol also has serious downsides, especially in modern, high-speed environments.

• Scalability issues: The 15-hop limit makes it unsuitable for large networks. Anything beyond that is simply unreachable.
• Slow convergence: When a change happens in the network, Routing Information Protocol takes time to update all routers. This slow convergence can cause delays or routing issues.
• Lack of advanced metrics: This protocol only counts hops. It doesn’t consider factors like bandwidth, latency, or load. So, it might pick a route that’s technically shorter but much slower or less stable.
• Security Concerns: Earlier versions, particularly RIPv1, have no authentication mechanisms, making networks vulnerable to malicious route updates.

Conclusion

The Routing Information Protocol may no longer be the star of the show, but it laid the groundwork for the dynamic routing systems we rely on today. Its simple structure, easy configuration, and low resource requirements make it a great choice for learning and small-scale applications. If you’re managing a complex or mission-critical network, you’ll likely want to use something more robust. But if you’re just getting started or managing a smaller environment, this protocol still has something to offer.