RDP from Internal to DMZ not working

Question

Hi UTM Community, 
 I'm trying to get standard RDP working from our internal network to a server located in our DMZ. 
 I can ping the server via IP/name from internal no problems. 
 The rules I've set are (source/protocol/destination) "Internal (network)" - "RDP" - "DMZ (network)" - Allow. Also tried more a more granular "internal PC" - "RDP" - "Server in DMZ" - Allow. Finally "Internal (Network)" - "ANY" - "DMZ (network)" - Allow. 
 None of the above seems to be allowing traffic. Each time I try to connect I get:

13:00:51

Default DROP

TCP

10.150.46.3

:

3389

&rarr;

10.150.0.2

:

59868

10.150.46.3 is the server in DMZ I'm trying to RDP to 10.150.0.2 is the workstation in INTERNAL I'm connecting from. 
 One thing that I&rsquo;ve noticed in comparing the log with other working rules is the source and destination addresses are the opposite way around. I think this is likely my problem? 
 For example a rule that IS working is &ldquo;Server in DMZ&rdquo; (10.150.46.3) &ndash; 32001 &ndash; &ldquo;Server in VS-002&rdquo; (10.150.2.2) &ndash; Allow. The log shows:

12:59:49

Packet filter rule #35

TCP

10.150.46.3

:

60481

&rarr;

10.150.2.2

:

32001

On the rule that is failing I would have thought the log should be 10.150.0.2:59868 -> 10.150.46.3:3389 
 So it appears I&rsquo;m setting up the rule the wrong way, can anyone point me in the right direction? 
 Appreciate your help.

ICT123 · Accepted Answer

Thanks for your input Sibtel, I've resolved the issue. 
 
It was a network configuration issue on the router sitting behind the UTM. Internal traffic destined for the DMZ network was being routed directly, bypassing the UTM completely. 
 
For anyone that has a similar issue in the future, trace route is your friend :)