We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is a Routing Domain?

By S.A. Keel
Updated May 16, 2024
Our promise to you
EasyTechJunkie is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At EasyTechJunkie, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

A routing domain is a term used to identify a lower level of a computer network hierarchy with respect to network traffic routing. All of the computers and routers contained under the domain must be administered by a single source, such as a company or organization, and adhere to a single routing protocol. Additional sub-networks may exist within a given domain in order to detail a network topology, so long as the subnets follow the same routing protocol. Furthermore, a particular domain may exist as part of a larger network.

The way a routing domain fits into the overall hierarchy depends somewhat on the construction of the network and the routing protocols used. It is often a subnetwork of what's known of as an administrative domain, which may have any number of routing domains within it. This way, two different routing domains may be operating under different routing protocols within a single administrative domain, but still be administered by a single source. Two or more administrative domains can also be connected in the case a third routing protocol need be implemented, but will be kept separate from the other two.

Stepping up in the hierarchy, an administrative domain may exist in what's known of as an autonomous system. An autonomous system can essentially be viewed as any collection of routing domains that have an established route to the Internet. In most cases, a single administrative domain and its routing domain will be an autonomous system, also sometimes termed a congruent domain. This is because in order for network traffic to get to another administrative domain, it usually has to traverse the Internet to reach the second administrative domain.

The way a routing domain works is through the use of an explicitly established routing protocol. Inside, there are any number of computers, referred to as end systems (ES). Connecting them into groups are typically routers, or other networking devices, that are termed intermediate systems (IS). These groupings, or subnets, are referred to as end system to intermediate system (ES-IS) protocols. The protocols that group up the intermediate systems which share the common routing protocol are referred to as an intra-domain intermediate system to intermediate system (IS-IS) protocol.

While the rules for routing domains specify that a single routing protocol be used throughout the domain, there are occasional exceptions. For example, a single ES can have a direct path to an IS. Technically, this can be viewed as another routing protocol, since the route is established between the ES and IS, though it doesn't interfere with the primary intra-domain IS-IS protocol. In general, an intra-domain IS-IS protocol is often referred to as an interior gateway protocol (IGP).

Since it is possible to have multiple routing domains within a single administrative domain, there are methods for interconnecting those instances where multiple administrative domains need to connect. In this case, a protocol different from the one used by the routing domain may be used to connect the two administrative domains. This is known of as an inter-domain IS-IS protocol. While two administrative domains managed by a single administrative source may exist, for the sake of security, they are typically connected via what's referred to as a border gateway protocol (BGP).

EasyTechJunkie is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.

EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.