# SR-MPLS over Unnumbered Interfaces

DevFeed: [SR-MPLS over Unnumbered Interfaces](<https://devfeed.tech/articles/sr-mpls-over-unnumbered-interfaces-11403.md>)

Original publisher: [Read original article](<https://blog.ipspace.net/2026/06/sr-mpls-unnumbered/>)

Published: 2026-06-01T06:03:00Z

Content type: tutorial

Language: en

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

Topics: [SR-MPLS](<https://devfeed.tech/topics/sr-mpls.md>), [IS-IS](<https://devfeed.tech/topics/is-is.md>), [networking](<https://devfeed.tech/topics/networking.md>), [Protocol (disambiguation)](<https://devfeed.tech/topics/protocol.md>)

Tags: [container](<https://devfeed.tech/tags/container.md>), [demo](<https://devfeed.tech/tags/demo.md>), [examples](<https://devfeed.tech/tags/examples.md>), [github](<https://devfeed.tech/tags/github.md>), [implementation](<https://devfeed.tech/tags/implementation.md>), [installation](<https://devfeed.tech/tags/installation.md>), [interfaces](<https://devfeed.tech/tags/interfaces.md>), [ipv4](<https://devfeed.tech/tags/ipv4.md>), [is-is](<https://devfeed.tech/tags/is-is.md>), [mpls](<https://devfeed.tech/tags/mpls.md>), [netlab](<https://devfeed.tech/tags/netlab.md>), [network](<https://devfeed.tech/tags/network.md>), [protocol](<https://devfeed.tech/tags/protocol.md>), [routing](<https://devfeed.tech/tags/routing.md>), [sr-mpls](<https://devfeed.tech/tags/sr-mpls.md>), [traffic-engineering](<https://devfeed.tech/tags/traffic-engineering.md>)

## AI overview

This tutorial demonstrates SR-MPLS over unnumbered IPv4 point-to-point interfaces using netlab and IS-IS. It explains the resulting SR-MPLS and IS-IS advertisements, including adjacency and prefix segments, and provides steps for trying the lab through GitHub Codespaces and an Arista cEOS container.

## Source excerpt

After the simple SR-MPLS demo and the dual-stack SR-MPLS setup, it was time for the next obvious question: Does SR-MPLS work over unnumbered IPv4 interfaces1, assuming the implementation of the underlying routing protocol supports them? Of course it does; let's go through the details, using the same topology I used throughout the Segment Routing workshop @ ITNOG10. Read more ...