I have a Sonicwall TZ firewall and I am trying to set up a VPN to a Fortigate Firewall. I control the Sonicwall and a 3rd party controls the Fortigate. We have gone over the configuration step by step a dozen times to make sure our settings match.
We are using Main Mode / AES-256 / DH5 / SHA1 / 28800 for Phase 1. We are using ESP / AES-256 / DH5 / SHA1 / 3600 for the phase 2 settings. Subnets on each side are 192.168.173.0/24 to 192.168.10.0/24 respectively.
Phase 1 negotiation completes, but Phase 2 does not. The Sonicwall Logs says phase 2 quick mode start. But there is never a reply. the IKE negotiation eventually times out.