WiFi Radius over IPSec

Hi there, 

I´m having a hard time understanding some RADIUS authentication issues. 

For better understanding, a sketch of my setup:

We have a UTM with Wireless Protection in the Head Office. We have a running Authentification with RADIUS for some APs there, which works fine.

We have a Guest Network with WPA2 PSK Authentification and an Internal Net with RADIUS Authentication (by MS NPS Server).

1. To test RADIUS over IPSEC i build a Testsetup within our LAN. So the aWAN Interface of the XG gets a IP in the Client Network an builds up it´s IPSec Tunnels.

To register the AP in the "Testbranch Office" I setup the DHCP Server for the AP with the DHCP Option 234 "Magic IP", pointing at the listening Interface of the UTM (192.168.250.254)

Everything works like a charm. The Config is posted to the AP and both SSIDs work like expected.

Now the Problem:

I took the whole Branch Office Setup (XG, VLAN Switch, AP and the Laptop) which are working in the internal Network and place it behind a real WAN Connection.

Guess what, the WPA PSK Setup is working, but the RADIUS Authentification runs in a time-out.

The TCP Dump of a working connection (in the internal Testsetup) looks like this: AP-> 414 -> Magic IP and backwards

The Request is send to the RADIUS and shows up in the logs.

In the WAN Setup there is no Log entry in at the RADIUS Log. I can see this in the wirless log:

2021-10-11 21:06:33Firewallmessageid="00005" log_type="Firewall" log_component="ICMP ERROR MESSAGE" log_subtype="Allowed" status="Allow" con_duration="0" fw_rule_id="5" nat_rule_id="0" policy_type="1" user="" user_group="" web_policy_id="0" ips_policy_id="0" appfilter_policy_id="0" app_name="" app_risk="0" app_technology="" app_category="" vlan_id="" ether_type="IPv4 (0x0800)" bridge_name="" bridge_display_name="" in_interface="ipsec0" in_display_interface="ipsec0" out_interface="" out_display_interface="" src_mac="f0:af:85:9a:ee:8f" dst_mac="" src_ip="192.168.250.254" src_country="R1" dst_ip="192.168.251.10" dst_country="R1" protocol="ICMP" icmp_type="3" icmp_code="3" packets_sent="0" packets_received="0" bytes_sent="0" bytes_received="0" src_trans_ip="" src_trans_port="0" dst_trans_ip="" dst_trans_port="0" src_zone_type="LAN" src_zone="LAN" dst_zone_type="" dst_zone="" con_direction="" con_event="Interim" con_id="3222778674" virt_con_id="" hb_status="No Heartbeat" message="" appresolvedby="Signature" app_is_cloud="0"

I don´t understand the difference.

I read about the NAT Rule for WAN Interface etc. but the WAN IP isn´t talking to the UTM. I can see, that the AP is talking to the Magic IP and the UTM forwards the request to the RADIUS an back to the AP.

So the communication should use Port 414 between AP and Magic IP(UTM) and this happens and works in the Test Setup. 

What am I missing?!

Thanks in advance!