We use WingFTP running in multiple environments, the majority running fine on Windows servers, but we are running into an odd issue on our CentOS 7 Apache web server.
We have 6 domains setup here, and two of these domains get the bulk of their use through uploading and downloading custom files that get generated by software they've made. This is all happening in the background over standard port 21 connections.
Randomly, for these two domains only, they will stop allowing port 21 connections, but continue to work through the web portal. A server restart gets them working immediately, and the domain logs show nothing after a certain point.
Any assistance would be helpful, if any additional information is needed, let me know.