Question : I keep getting "there is no citrix presentation server configured on the specified address" when using citrix outside of my network

I have a slightly complicated Citrix Environment.

I have a Secure Access Gateway, Web Interface Server, and two Presentation servers.  For some reason when I try to access an application remotely, it doesn't work, but when accessing the application from the internal network everything works fine.

I have the Secure Access Gateway on the external network, as well as on the internal network, second NIC has no default gateway so external is the default network.

The web interface and two farm servers are all on the same network, as is the second NIC of the Secure Access Gateway.

I know I'm missing something, I'm just not sure what.

Answer : I keep getting "there is no citrix presentation server configured on the specified address" when using citrix outside of my network

SG to/from WI: 443 & 80
SG to/from PS: 1494, 2598, xml port