GTM Translation doesnt work with Generic Host

GTM version 10.2.3. Not VE.

We have a requirement to configure a Generic Host as it is not behind any LB. We need the DNS to resolve to the Public address. The GTM, the real server is residing in DMZ and same subnet as the GTM self IP. We are using private IPs in the DMZ. Natting happens on the firewall.

I add the Generic host to GTM with the following settings.

Address: Public IP (say y.y.y.y)

Translation: Private IP(say x.x.x.x)

Under Virtual Servers

Address: Public IP (say y.y.y.y)

Service Port : 444

Translation: Private IP(say x.x.x.x)

Translation Service Port : 444

Then I create a pool add the VS as a member and use tcp monitoring. the pool and the member shows down with the above settings.

However with the following settings the pool works but Wide IP resolves to the private IP rather than public:

Address: Private IP(say x.x.x.x)

Service Port : 444

Translation:Public IP (say y.y.y.y)

Translation Service Port : 444

But translation works fine on the servers added through the LTMs.

Any help much appreciated.

Regards