How to Fix Internet Connectivity Issues on FortiGate Like a Pro!
Check out this video to learn how to troubleshoot Internet connectivity issues on FortiGate.
00:00 Introduction
00:34 Make sure that the FortiGate is powered on
00:41 Topology
01:03 Check the WAN Interface make sure it's up and running and L2 is working and IP is setup on the WAN interface
01:35 Make sure that the Gateway is pingable
01:48 Check and verify the ARP table
02:33 Use Sniffer to check arp traffic
02:56 How to clear ARP table on FortiGate
03:17 Making sure FortiGate arp request and arp response is sent using sniffer
04:20 Check if ISP is doing MAC address filtering and how to set FortiGate Interface MAC address
05:20 Check if there's a default route configured on the FortiGate
05:40 How to show routing table database to show inactive routes
06:38 Check the FortiGate DNS setup
07:14 When user behind the FortiGate is not able to do DNS resolution
07:50 Using sniffer to make sure DNS traffic is going through the FortiGate
08:50 Make sure there's a firewall policy from internal to external interface
09:20 Check policy route
10:20 Check if Virtual IP or VIP is configured for the WAN interface
12:03 Check if there's a switch between the FortiGate and the internet router
13:05 Use sniffer to check why user don't have internet connection
13:54 Use debug flow to check why user don't have internet connection
14:50 Check interface status and interface speed