older IOS compatibility to NPS Windows Server 2019.

[mnakano]

Good afternoon, 

Part networking person in training and mainly a sys admin. I am upgrading my Windows 2008 (eol) to Windows 2019 Server to host my NPS (radius server). Our switches are mixed with 3850's 3650's 9300's and 4500. IOS for older switches are in 3.x IOS and some are up to date > 10.x. Cores 6513 are not on NPS/Radius authentication for security reasons.

Is there any issues with older IOS communicating to a Windows 2019 server w NPS? I've seen only 2016 in other forums but not in 2019.

[Seb Rupik · Accepted solution]

Hi there,

The RADIUS protocol is well established and as such not subject to many updates. It is unlikely that any thing has changed in the microsoft implementation between those server versions. So long as the new server is listening on TCP/UDP ports 1812 and 1813 it should be fine. It should also be completly oblivious of the software versions that connecting clients are running.

cheers,

Seb.

[mnakano]

Thank you, makes sense that the switches care about the communication between the ports to the radius/nps.