Microsoft update kills some VPN

Microsoft’s recent security update for Windows 10 & 11 has caused some significant problems as it breaks established L2TP vpn connections

After installing the recent Windows 10 KB5009543 and Windows 11 KB5009566 cumulative updates for 11/01/22 users started reporting L2TP VPN connection errors.

Several of our bigger clients use VPN’s to connect to their work environments from interstate and working from home.

After finding out the cause we immediately removed the updates from the patching schedule and then set about removing them from the affected systems – It has been a very busy Friday morning.