We have set up a router with two DSL links using PCC. Works great for everyone except one user with a Macintosh. From linux and PC clients all services work fine (FTP, HTTP, HTTPS, Skype). On the Macintosh (10.0.6.8 Snow Leopard) everything works except FTP when using the PCC link. If we connect direct to the Internet using LTE modem, then the Macintosh FTP works fine.
The problem is only with upload of files. Download and remote FTP commands like delete work fine. The file appears to upload, but never does. Tried every FTP client we could find for Mac and all do the same. Tried active vs passive. Tried extending retries and timeouts. We have turned on proxy on our router to bypass PCC. We have tried to create rules to route FTP only to one of the two connections. Nothing seems to fix this other than not using PCC. The local Macintosh firewall is off.
Has anyone else come across this? Only Macintosh has the problem.