Troubleshooting Tip: Internet Connectivity issues if DHCP is enabled on a LAN port

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Description	This article describes how to resolve internet connectivity issues that may occur if DHCP is enabled on a LAN port.
Scope	FortiGate.
Solution	If DHCP is enabled on LAN port and "Retrieve default gateway from server" is enabled  In this case, a default route from LAN interface to 0.0.0.0/0 would exist in the routing table which will not allow the traffic to go to the WAN interface. Check the firewall policies to ensure there is a policy from LAN to WAN. Configure Firewall policy on FortiGate. Check the routes in the CLI using 'get router info routing-table all'. Check a route exists from a LAN port to 0.0.0.0/0. Disable 'Retrieve default gateway from server' from the LAN port. Check the routing table again. The route from LAN to 0.0.0.0/0 must be deleted and the devices for the LAN network to receive internet connectivity.