OpenVPN Support Forum

Hi,

I do not use (and want) duplicate-cn: my remote users get IP address, mask, dns, etc etc from the server.

Sometimes it happens that, erroneously, a client connects using the cert of another, already connected, client.

The result of this error is that the connected client is disconnected and the 2nd one becomes connected. After 5secs, the disconnected one restarts and disconnects the other and this is an infinite loop.

I would like to set OpenVPN in such a way a client cannot connect if there is a client with the same cn already connected.
I tried, without success, single-session
Is this possible?
Thank you for your help!!

Francesco

you'll need a 'tls-verify' or 'client-connect' script for this, which checks the incoming cert against a file/database and then decides whether the certificate is allowed to log on ; a corresponding 'client-disconnect' script would then clear the entry in the file/database.

You may have to use 'duplicate-cn' to allow the second client to log on (and fail) during the 'tls-verify' step.