Incorrect NAT policies preventing hosts from accessing the internet.

Incorrect NAT policies preventing hosts from accessing the internet.

Step 1: To troubleshoot, setup a continuous ping to 8.8.8.8 on the server and take a packet capture on the SonicWall of ICMP traffic going to 8.8.8.8

We see that the outbound ICMP traffic (a ping) is NAT'ed to an internal IP address that is leaving the SonicWall. This ping request will never be returned because of the LAN addressing going out to the WAN. Capture shows traffic coming in from X0 (good) and leaving X1 as an internal IP (bad).

We went to the NAT policy table and located a bad NAT that was taking priority before the auto-added X1 outbound NAT policy