I am using the following guides to set up OVPN server, using a certificate from CACert:
http://wiki.mikrotik.com/wiki/OpenVPN_C ... ep_by_Step
http://wiki.mikrotik.com/wiki/OpenVPN#C ... CAcert.org
Immediately after importing the certificate-response.pem file (the cert from CACert), free memory begins dropping steadily for about 15 seconds, before it suddenly nosedives to around 4mb, CPU usage hits 100%, and the router drops all connections for a little bit. Once I can get back into winbox, the free memory countdown has already begun again. This cycle repeats about every 30 seconds, indefinitely. When I delete the imported cert, the memory usage stabilizes, but the CPU stays at 100% until I reboot the router.
This is repeatable in my environment, I cannot get it to import the certificate without immediately becoming unstable.
This is on an RB2011iL-RM.