VNS3 has successfully negotiated IPsec tunnels with all leading extranet hardware devices actively supported by the vendor (and some that are out of life and out of support).
Most models from Cisco Systems*, Juniper, SonicWALL, Netgear, Fortinet, Barracuda Networks, CheckPoint*, Zyxel USA, McAfee Retail, Citrix Systems, Hewlett Packard, D-Link, WatchGuard, Palo Alto, OpenSwan, pfSense, and Vyatta.
Checkpoint R65-R77 requires using Native IPSec, as Checkpoint does not conform to NAT-Traversal standards.
Cisco ASA 8.4(2)-8.4(4) bugs often prevent a stable connection from being maintained.
[Watch on YouTube: https://youtu.be/Wt0D8RzPz1E]