I have been trying to setup a site to site VPN between two of our buildings for the last 3 days. On one end (new building) I have a brand new SonicWALL NSA 3600 with just the basic settings (static IP, subnet, etc). On the other end (headquarters) I have an older SonicWALL NSA 3500. This NSA 3500 has 4 other site to site VPN's already working (one of which is to another SonicWALL TZ210). I am running into a problem with the new site to site vpn where I cannot get the connection established.
I am using IKEv2 on both ends, the same DH group, the same encryption (AES-256) and still nothing. Here is the log I see on my NSA 3500
IKEv2 Received notify error payload
IKEv2 Initiator: Received IKE_AUTH response
IKEv2 Initiator: Send IKE_AUTH Request
IKEv2 No NAT device detected between negotiating peers
IKEv2 Accept IKE SA Proposal
IKEv2 Initiator: Received IKE_SA_INT response
IKEv2 Initiator: Send IKE_SA_INIT Request
Double and triple checked the pre-shared keys and IP addresses. Any suggestions?