pta200 - Thanks for posting your question on the forum!
The important thing to remember when configuring this application is mainly 2 points:
1. The VPN selectors must match what the source and destination IP will be AFTER the traffic has been NATted.
2. Instead of having an ALLOW in your firewall rules for VPN traffic, you will need to configure NATs for this traffic.
The following thread has an example configuration in it that you may find helpful: Re: Same destination LAN on each end of a VPN tunnel.
Also, example #2 in the guide below has a similar setup with a sample configuration as well:
Please do not hesitate to let us know if you have any questions.
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