jasailafan  Master Member

It seems a known limitation on ATP model.

ZYXEL firewall uses a self-signed certificate, so you need to install a valid 3rd party certificate with full chain to the firewall. In this post, you can find how to import root certificate, intermediate certificates and end-entity certificate to the firewall.

Would you like to authenticate the wireless users that connect to the ATP500 using WPA2-Enterprise (802.1X)? If so, I think you should configure RADIUS in AAA Server instead of AD.

Need to enable IGMP on the interfaces. Here is an example. https://support.zyxel.eu/hc/en-us/articles/360004093659-IPTV-with-multicast-and-IGMP-USG-ATP-VPN

Both the browser and website support HSTS. Here is a similar post.

Which secuextender version is installed? IPSec_SSL_VPN_7.7.40.019 for Windows or IPSec_SSL_VPN_3.2.4.19 for macos?

Seems a known issue on macOS 14 Sonoma. I tired to set a value smaller than 1440 in phase 2 SA life time but macOS 14 still disconnects exactly after 24 minutes. https://github.com/feedback-assistant/reports/issues/448 https://forums.developer.apple.com/forums/thread/742731

What's the firmware version on USG2200-VPN? Is the AP managed by USG2200-VPN? When the wifi client has no internet connection, try to ping the gateway IP from the wifi client and ping any external IP from the USG2200-VPN respectively to clarify the issue.

You can check if the connectivity check is enabled on ge2_ppp.

You can find a configuration guide in the DPF file "How to configure the VPN settings if two sites are using the same network subnet" in this discussion.

It seems this function should be handled by switch, not the firewall.

Because the AD is at the remote site over IPSec VPN, try to configure a static route on USG Flex 700. Destination IP: 192.168.20.0 Subnet Mask: 255.255.254.0 Interface: Select the lan interface which is the local policy configured for Site-to-Site VPN

Could you describe the way you access caldav? Is it a caldav server in lan and you'd like to access it through NAT from wan(DDNS)?

Here are some examples using strongswan on Linux to establish vpn. I hope these will help. https://community.zyxel.com/en/discussion/15678/usg-flex-200-no-proposal-error-with-strongswan https://community.zyxel.com/en/discussion/9890/i-can-connect-from-windows-10-but-cant-from-linux

Seems CA is invalid. Do you select the default certificate?