Re: IS-IS Flat Network Size
Mikael Abrahamsson via NANOG <[email protected]> Tue, 28 Jul 2026 08:13:30 +0200 (CEST)
| Newsgroups | gmane.org.operators.nanog |
|---|---|
| Organization | People's Front Against WWW |
| Message-ID | <[email protected]> |
On Mon, 27 Jul 2026, Tom via NANOG wrote: > 1) Is anyone running a flat IS-IS L2 network with approx 300 routers? If not, what is the higher end you've seen? As others have stated, 300 routers is (at least) 1-2 orders of magnitude lower than "this could be a problem" with modern hardware. What I'd start to consider at (much) higher numbers than yours is number of routes you have in IS-IS, considering FIB update speed is in the order of tens of thousands per second on most hardware assisted platforms. This means that if you have tens of thousands of routes, you want to make sure the platform you're using updates the important nexthops first (for instance loopbacks) in the FIB, otherwise your covergence time suffers. -- Mikael Abrahamsson email: [email protected] _______________________________________________ NANOG mailing list https://lists.nanog.org/archives/list/[email protected]/message/A46AIQD4WPUSQA3OQZ5E5TEVZ24B6THY/