When you run a database on your Windows CE device, you must configure a proxy port for ActiveSync so that requests are passed down to the database running on the Windows CE device.
Open Interactive SQL.
From the SQL menu, choose Connect.
The Connect dialog appears.
Click Tools and then choose Setup Windows CE Proxy Port.
The Windows CE Proxy Ports dialog appears.
The New Proxy Port dialog appears.
Type SQL Anywhere in the name field.
Type 2638 in the Port field.
This is the default TCP/IP port for SQL Anywhere.
Every time your Windows CE device is cradled, ActiveSync forwards traffic on port 2638 to the device. If you start a database server on your computer while your Windows CE device is cradled, it cannot use the default port 2638. If this is problematic, you can choose another port to dedicate to Windows CE traffic.
When setting up or changing a proxy port, it may be necessary to log off and then log in to your Windows desktop in order for the new proxy port setting to take effect.
You can also configure a proxy port by setting the following registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows CE Services\ProxyPorts. Name the DWORD value SQL Anywhere and specify the port dedicated to Windows CE traffic (2638 is a good choice).
Modifying the registry is dangerous. Modify the registry at your own risk.