# Do You Need IS-IS Areas?

DevFeed: [Do You Need IS-IS Areas?](<https://devfeed.tech/articles/do-you-need-is-is-areas-11309.md>)

Original publisher: [Read original article](<https://blog.ipspace.net/2026/01/is-is-areas/>)

Published: 2026-01-14T07:45:00Z

Content type: opinion

Language: en

Sources: [ipSpace.net blog](<https://devfeed.tech/sources/ipspace-net-blog.md>)

Topics: [IS-IS](<https://devfeed.tech/topics/is-is.md>), [networking](<https://devfeed.tech/topics/networking.md>), [migration](<https://devfeed.tech/topics/migration.md>)

Tags: [github](<https://devfeed.tech/tags/github.md>), [is-is](<https://devfeed.tech/tags/is-is.md>), [network](<https://devfeed.tech/tags/network.md>), [networks](<https://devfeed.tech/tags/networks.md>), [ospf](<https://devfeed.tech/tags/ospf.md>), [routing](<https://devfeed.tech/tags/routing.md>)

## AI overview

The article explains when IS-IS areas are useful. Most networks can likely operate with a single area, but hierarchy can help with fault isolation and route summarization, especially on constrained hardware. It recommends checking device capabilities because some implementations may not support inter-level prefix propagation.

## Source excerpt

TL&DR: Most probably not, but if you do, you'd better not rely on random blogs for professional advice #justSaying 😜 Here's an interesting question I got from a reader in the midst of an OSPF-to-IS-IS migration: Why should one bother with different [IS-IS] areas when the routing hierarchy is induced by the two levels and the appropriate IS-IS circuit types on the links between the routers? Well, if you think you need a routing hierarchy, you're bound to use IS-IS areas because that's how the routing hierarchy is implemented in IS-IS. However... Read more ...