VPN sometimes doesn't allow communication and/or has severly poor performance until restart

autobottodoggo · Post by **autobottodoggo** » Mon Jun 03, 2024 1:45 am

Setup:

- Rocky Linux 8.9 (selinux disabled)
- two NICs
- SEVPN 5.02 Build 5180 (dev version)

The system has two NICs to get around the Linux limitation of being unable to access resources on the same IP as SEVPN (I couldn't get the tap driver going, so adding a second card was just ... simpler). Using SEVPN dev to allow the ListenIP config param.

Two problems seem to occur randomly at boot and VPN server start:

- clients are unable to access resources on the server (using the IP on which the SEVPN is not listening)
- performance from VPN clients is severely slow (<1mbps on a 50mbps link)

Sometimes rebooting the system solves one or the other problem. Sometimes stopping/starting SEVPN solves one or the other problem. Sometimes both are needed to solve the problems in one order or the other.

What could be causing this?