SFTP Transfers Failing at 1GB - KB Article #1774Related Articles --
An issue has been discovered in Serv-U which causes transfers to fail after transmitting 1GB of data via the SFTP (over SSH2) protocol. Serv-U versions 220.127.116.11 and up correct this issue.
The issue would occur during the "key re-exchange" step of the connection, which occurs after every 1 GB of transfer per the SFTP standard. Because Serv-U did not use the previous prevoius SSH Session ID properly it would not acknowledge subsequent packets sent by the server, causing the connection to terminate. Most clients will automatically reconnect and resume transfers, but to correct the problem for clients that do not reconnect Serv-U must be updated to 18.104.22.168 or newer.