F-Secure Internet Gatekeeper for Linux/Administrator’s Guide
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1 The following is sent to the server:
500 Unknown Command: "[Command received]" ([Product name])
11.10
POP Commands – Operations
During POP connections, commands executed from clients are operated in the following way.
The [Product name] is by default "F-Secure/fsigk_pop/Version/Host name".
You can change the product name by editing
"product_name="
(see expert options for details).
Client connections
1 If “Defining parent server by user” is disabled or transparent mode is enabled:
①
The server is accessed.
②
If access fails:
1)
The following is sent to the client:
-ERR Can't Connect to (Server host: Server port)
errmsg=[Connection error message]
For connection error messages, see “
Connection Error Messages
”, 162.
2)
The session ends.
③
Receives a response from the server.
④
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:
+OK [Product name] starting.
Command lines
1 If a line is greater than 998 bytes:
①
The following is sent to the client:
-ERR Too long line
2 If not connected to a server and a command other than USER/QUIT is sent:
①
The following is sent to the client:
-ERR please use USER command at first.
3 If 1 and 2 above do not apply, the command is executed.
USER command
1 If “Defining parent server by user” is disabled or transparent mode is enabled:
①
The following is sent to the server: Client response information
2 If (1) above does not apply:
①
If user authentication is enabled:
1)
If the user is not added:
a)
The following is sent to the client:
-ERR Invalid Account Auth.
②
If the user name contains “@” or “#”:
1)
The server specified by the last “@” or “#” is accessed.
③
If (2) above does not apply:
1)
If the parent server is empty:
a)
The following is sent to the client:
-ERR USER format is USER username@hostname or
username#hostname
b)
The command terminates.
2)
Connects to the parent server.