Why I can't access VPN peer gateway Web GUI by remote interface IP?

Zyxel_James

Scenario:
I have two USG FLEX H Firewalls configured Site-to-Site tunnel between them. However, I found out I can't access the local Web GUI through the tunnel from the remote side.

Question:
Why I can't access VPN peer gateway Web GUI by remote interface IP even when a Policy Route is configured?

Answer:
Local out traffic from the firewall itself won't go into the tunnel. And Policy Route can't control the local out traffic of the firewall itself, while Static Route can.
So you need Statis Route to direct the return local traffic to the VPN tunnel.