We have an ATT Arris 5268AC gateway that had dynamic IP internet service and was passing traffic flawlessly to a Sonicwall TZ400. Last night traffic stopped being passed. When connected directly to the gateway with an independent client (desktop) we can get WAN access and see our public IP no issues. ATT convinced us to buy a block of static IPs to fix the problem but no luck. I need to 5267AC to pass all WAN traffic to the TZ400 as no user behind the firewall have any WAN access at the moment. We are on our failover comcast circuit at the moment but need to resolve this. The Sonciwall provides DHCP and inherits DNS from the WAN.