FirewallUser@FTPServer Authentication Command Sequence
The FTP Client uses the following command sequence to make a connection when you have configured Style to FirewallUser@FTPServer in the Firewall section of the Security Properties dialog box.
OPEN <Firewall_server>
USER <Firewall_username>@<FTP_server>
PASS <Firewall_password>
USER <FTP_username>
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