ICSA Labs (see the Resources section) has certified 26 gateways/switchers from 16 different vendors as being compliant with IPSec and being interoperable with each other. Also, there are four client-side software packages it has certified that will operate with the certified gateways under static IP conditions.

The use of static IP conditions implies that the dynamic addresses assigned through DHCP or NAT might not always work correctly through heterogeneous gateways. It's up to the product specifier to make sure that any impact on the proposed usage of these products is understood.