I have had problems with ftp, more than anything else, since I began using Linux. I have Vsftpd installed and I know that, generally, it works; I recently repaired a guy's PC and downloaded from my own server at his store. I have downloaded from an appliance store that had a public PC (just to test my server). This is on RedHat Enterprise and, frankly, I'm not sure which build of vsftpd I've got but I don't think this issue is build-dependent.

The problem: a couple of very computer savvy folks cannot log into my linux server but if I switch the ports around they can log into a windows box running Bulletproof ftp. In both cases the ports I've opened are 20 and 21 and I've also put the server(s) in the router's DMZ. So everything is identical but people cannot log into Vsftpd whereas they are able to log into Bulletproof. In my vsftpd conf file I have both pasv and port connections enabled..... And, again, this is only with a few people but clearly they are not firewalled or anything as they can immediately log into the Windows server.

This is driving me crazy. Anyone know what could cause this?

Thanks very much

Errors always help, on your server and from the clients end?