If I look into the connection table then I fail to find what IP-address the Hotspot users are using.
What outgoing address does the Hotspot NAT is using?
[admin@Jeekim] ip hotspot host> print
Flags: S - static, H - DHCP, D - dynamic, A - authorized, P - bypassed
# MAC-ADDRESS ADDRESS TO-ADDRESS SERVER IDLE-TIMEOUT
0 P 00:0C:90:4B:25:35 192.168.29.50 192.168.29.50 hotspot1 5m
1 P 00:0C:E5:4C:41:50 192.168.39.12 192.168.39.12 hotspot1 5m
2 P 00:0C:E5:4C:41:50 192.168.39.13 192.168.39.13 hotspot1 5m
3 HA 00:0C:E5:4D:77:B3 192.168.200.94 192.168.200.94 hotspot1
[admin@Jeekim] ip hotspot host>
The MT box with a hotspot has no interface with a public IP-address - all internal.If you have more than one public (WAN) IP it seems Mirkotik picks the "highest number" one - at least after a reboot. Not sure if this is always true though. Have you tried using Torch on both the public and private interfaces to trace a given connection? Note that you have to uncheck the port checkbox in torch to see anything other than tcp/udp.