I have a Sonicwall Pro3060 and a Cisco EPC2425 router. I have setup a site-to-site VPN and it won't connect. All the settings are the same on both ends and the security matches, but on the Cisco I can see:
Failed ESP packet internal IP on CIsco subnet > internal IP on Pro3060 subnet
PatcketEncapsulate failed with error bad sequence number
Then in the Sonicwall logs I don't really see anything.
When I'm setting up the VPN on the Cisco end it gives me the option to automatically use the WAN IP, but when this is ticked I get an IP address that starts with 10.x.x.x. However, if you go to whatsmyip.com and run that from one of the computers behind it it gives you something with 95.x.x.x.