3com 5500-ei pwr Guía De Referencia

 

1-20 

Use the passive command to set the data transfer mode to the passive mode. 

Use the undo passive command to set the data transfer mode to the active mode. 

By default, the passive mode is adopted. 

The differences between the passive mode and the active mode are: 

z 

When working in the active mode, an FTP client advertises a random port Port1 to an FTP server 

through TCP port 21; upon receiving the advertisement, the FTP server initiates a connection with 

Port1 on the client for data transmission. 

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When working in the passive mode, an FTP client sends a passive request to the FTP server 

before data transmission, the FTP server advertises a local random port Port2 to the FTP client, 

and the FTP client establishes a connection with Port2 using a local random port. 

If an FTP client initiates a connection with an FTP server through a firewall, the firewall may block the 

connection request because the FTP server initiates the connection with Port1 through an external 

network, and thus data transmission will be affected. Therefore, you are recommended to set the data 

transmission mode of the FTP client to passive when accessing the FTP server through a firewall. 

# Set the data transfer mode to the passive mode. 

[ftp] passive 

% Passive is on 

put localfile [ remotefile ] 

FTP client view 

localfile: Name of a local file to be uploaded. 

remotefile: File name used after a file is uploaded and saved on an FTP server. 

Use the put command to upload a local file on an FTP client to an FTP server. 

If you do not specify the remotefile argument, the local file is saved on the FTP server with its original 

name. 

# Upload the local file named temp.c to the FTP server. 

[ftp] put temp.c  

227 Entering Passive Mode (2,2,2,2,4,13). 

125 ASCII mode data connection already open, transfer starting for temp.c. 

226 Transfer complete. 

FTP: 15 byte(s) sent in 7.549 second(s) 1.00byte(s)/sec.