IP packet with unknown IP version=15 seen

[Azmodes]

I've been seeing the warning from the thread title A LOT in my OpenVPN logs. Like 2,000 entries all at the same time and this dump seems to repeat every 15 minutes. I've googled a bit and tried playing around with the compression settings, since this error can apparently be caused by a server/client mismatch there. But the interesting thing is that the warnings keep coming even if no clients are connected to the server at all, like clockwork.

My server is configured via Servers [legacy].

Server config:
Server Mode: Remote Access (SSL/TLS + User Auth)
Authentication backend: Local db
Protocol: UDP
Device Mode: tun
Topology: net30
Compression: No Preference

Client export config:

Code: [Select]

dev tun
persist-tun
persist-key
data-ciphers-fallback AES-256-CBC
auth SHA256
client
resolv-retry infinite
remote **** udp
lport 0
verify-x509-name **** subject
remote-cert-tls server
auth-user-pass
auth-nocache
I have one CSO defined (to enforce a static tunnel IP), but as I said, the warnings keep coming in even if nothing is connected.

It's worth noting that my VPN works perfectly and clients can connect without issue. It's just these weird log entries that have me scratching my head and frankly make the logs a bitch to use. Running OPNsense 24.1.4-amd64, everything up to date.

[Azmodes]

Update: I had to reinstall OPNSense due to a faulty SSD and now the warnings are gone (configuration exactly the same after importing a backup config). *shrug*