What do you mean by "pereformance hit" - memory, cpu or both? Also how serious it is? Device used here is RB951 so quite weak device considering it's handling monitoring traffic and parking lot hotspot I'd need to perform some tests to give more detailed info but roughly what's the performance impact - 10, 50, 200, 1000%? Also - it's supposed to be using IPSec VPN now - doesn't VPN require conntrack anyways?
MTCNA, MTCRE, MTCINE