Forum Discussion
Site to Site VPN failed for no reason, cannot re-establish connection.
Hi all, This is basically as simple as the title suggests. From last Friday, a site to site VPN connection ceased working for no visible reason. There have been no changes to Azure config, or loc...
Please check on this:
1. Local Network Gateway IP
- Double-check that the public IP of your SonicWall is correctly entered in Azure.
- If your ISP changed your IP recently, Azure may still be trying to reach the old one.
2. Firewall/NAT Rules
- Ensure UDP 500 and 4500 are open and forwarded correctly.
- SonicWall logs may show outbound attempts, but Azure might be silently dropping them.
3. Azure Diagnostic Logs
Enable and inspect:
- IKEDiagnosticLog
- TunnelDiagnosticLog
- GatewayDiagnosticLog
These can reveal if Azure is receiving IKE packets or rejecting them.