GRE tunnel issues getting to websites

[gnussbaum]

Hello,

We use a Fortigate FG100 (7.2.8) and create a GRE tunnel to our Netskope tenant.  The tunnel shows as up on the tenant and shows up as a static route when I run "get router info routing-table all"

We have a test VLAN set up to test connectivity.  We have setup a firewall rule with the VLAN as the source and the GRE tunnel as the destination, allowing HTTPS traffic along with setting up a PBR for HTTPS

Am I missing something?  DNS and https isn't working.  I can't go to websites and can't ping any names or IP addresses.

[adambomb1219]

Routing?  What does Netskope say? 

[AEK]

Hi

Try initiate a simple ping and see if it is forwarded through the tunnel.

diag sniffer packet any 'host x.x.x.x and icmp' 4

Check the same on the remote site to see if the echo request packet is reaches the remote firewall.

[hbac]

Hi @gnussbaum,

So you only allow HTTPS? How about DNS? Which DNS server are you using? You can run debug flow to see if traffic is leaving the FortiGate or being dropped. Please refer to https://community.fortinet.com/t5/FortiGate/Troubleshooting-Tip-First-steps-to-troubleshoot-connecti...

Regards, 

[HarshChavda]

Hello, 

Please refer this document: https://community.fortinet.com/t5/FortiGate/Troubleshooting-Tip-Routing-Issue/ta-p/195727