F-Secure Internet Gatekeeper for Linux/Administrator’s Guide
159
④
If the connection fails:
1)
The following is sent to the client:
-500 Can't Connect to (Server host
:
Server port)
errmsg=[Connection error message]
For connection error messages, see “
Connection Error Messages
”, 162.
⑤
The following is sent to the server: USER [User name]
⑥
Receives a response from the server.
⑦
The following is sent to the client: [Server response information]
QUIT command
1 If connected to a server:
①
The following is sent to the server: [Client response information]
②
Receives a response from the server.
③
The following is sent to the client: [Server response information]
2 If (2) above does not apply:
①
The following is sent to the client:
221 Quit
PASV command
1 The following is sent to the server: PASV
2 Receives a response from the server.
3 The following is sent to the client: 227 Entering Passive Mode (xx,xx,xx,xx,yy,yy)
(xx is the IP address of the proxy and yy is the proxy port)
PORT command
1 The following is sent to the client: PORT (xx,xx,xx,xx,yy,yy)
(xx is the IP address of the proxy and yy is the proxy port)
2 Receives a response from the server.
3 The following is sent to the client: [Server response information]
RETR
/
LIST
/
NLST
/
STOR
/
STOU/APPE commands
1 If PASV/PORT commands are not executed:
①
The following is sent to the client:
530 please use PORT/PASV command at first.
②
The command terminates.
2 If the mode is PASV:
①
Waits for a data session to connect.
②
If the source of the data session and control session are different:
1)
The following is sent to the client:
530 Invalid Connection Source.
2)
The command terminates.
③
Connects to the server with the data session.
④
Receives a response from the server.
⑤
The following is sent to the client: Server response information
⑥
If the response code is other than 1xx:
1)
The command terminates.