Certificate Expiry

Hi,

I Have a Mikrotik router running on Amazon EC2 that is used as a VPN concentrator for some sites that I manage remotely.

I have my remote sites connecting to this via OVPN. This has been running nicely for a few day after I transitioned my clients to it after having used PPTP previously.

However I have now realised there is something that I failed to test. What happens when the OVPN server certificate/ self signed CA expires?

Will my client routers lose connectivity? Will I have to manually add a new certificate to each site?

Thanks for your help,
Regards,
-Callum