I have been thinking so far that FTP deosn't cause any bit errors while transferring files. But recently, I met a problem that the files I sent through FTP between my two servers are sometimes different. They makes different hash values with MD5 checksum algorithm. So I searched about FTP bit errors, I found some articles that TCP uses low level error detection so FTP also can makes bit errors.
Then, how much probability that FTP causes any bit error when transferring compressed files(.gz) which size is abount 10MB? And can I resolve this problem with SFTP instead of FTP? If not, how can I handle this?
My Environment
Source: WinSCP for FTP Client (Windows Server 2012 R2)
Dest: FileZilla for FTP Server (Windows Server 2012 R2)
Edit) In my case, the cause may not be FTP transmission error. I just wonder that the reason is FTP or others.
81 Answer
The universe causes bit-flips more frequently than you might believe. That's one reason that checksumming and error detection are accounted for in things like tftp. I wouldn't jump to blaming the protocol.
Is it possible that FTP makes any bit error?
Yes, but not the most likely suspect IMO.
And can I resolve this problem with SFTP instead of FTP? If not, how can I handle this?
Top of my list would be rsync, though it could be handled over ssh with cp/rcp (which would seem to be comparable to sftp.)
