I have done something similar to this in our application.
All you have to do to enable the FTP server and have a config file. Check the assigned IP address and if that's ok otherwise just reassign the IP from the config file.
Hint:
u32 lIpAddress, u32 lSubMask, u32 lGatewayAddr
//Get current configuration setting
code = customizeIamGetIfconfig("eth0", &ifConfig);
//Set current configuration setting
customizeSaveIPParameters(lIpAddress, lSubMask, lGatewayAddr);