F-Secure Internet Gatekeeper for Linux/Administrator’s Guide
142
Transparent mode (Router or Bridge), Passive FTP
Client
Internet Gatekeeper (0.0.0.1)
FTP server (ftpserver, 0.0.0.2)
TCP connect(to:
0.0.0.2:21)
----------------------------->
TCP connect(to:
0.0.0.2:21)
----------------------------->
220 ftpserver
<-----------------------------
220 ftpserver
<-----------------------------
USER user
----------------------------->
USER user
----------------------------->
331 Password required
331 Password required
<-----------------------------
<-----------------------------
PASS password
----------------------------->
PASS password
----------------------------->
230 User logged in.
230 User logged in.
<-----------------------------
<-----------------------------
PASV
----------------------------->
PASV
----------------------------->
227 Entering Passive Mode (0,0,0,2,0,2)
<-----------------------------
227 Entering Passive Mode (0,0,0,1,0,1)
<-----------------------------
RETR /file
----------------------------->
RETR /file
----------------------------->
TCP connect(To:
0.0.0.1:1)
=====================>
TCP connect(To:
0.0.0.2:2)
=====================>
150 Opening data connection.
<-----------------------------
150 Opening data connection.
<-----------------------------
(the rest is processed in the same way as in proxy mode)