Tuesday, September 29, 2015

FTP / VSFTPD - 1

FTP /VSFTPD INTERVIEW QUESTIONS AND ANSWERS 

PAGE - 1

1..What is ftp?

The File Transfer Protocol (FTP) is a standard network protocol used to transfer computer files from one host to another host over a TCP-based network, such as the Internet.

2..What does vsftpd stands for?
Vsftpd means very secure FTP daemon

3..Differentiate between active ftp  and passive ftp?

Active FTP
The sequence of events for active FTP is:
1. Your client connects to the FTP server by establishing an FTP control
connection to port 21 of the server. Your commands such as ls and get are
sent over this connection.

2. Whenever the client requests data over the control connection, the server
initiates data transfer connections back to the client. The source port of
these data transfer connections is always port 20 on the server, and the
destination port is a high port (greater than 1024) on the client.

3. Thus the ls listing that you asked for comes back over the port 20 to high
port connection, not the port 21 control connection.
Passive FTP works differently:

1. Your client connects to the FTP server by establishing an FTP control
connection to port 21 of the server. Your commands such as ls and get are
sent over that connection.

2. Whenever the client requests data over the control connection, the client
initiates the data transfer connections to the server. The source port of
these data transfer connections is always a high port on the client with a
destination port of a high port on the server.
Passive FTP should be viewed as the server never making an active
attempt to connect to the client for FTP data transfers. Because the client
always initiates the required connections, passive FTP works better for clients
protected by a firewall.

4..Explain max_clients parameter?

Maximum number of clients that can connect at one time. If set to 0, the number of clients is unlimited.

5..How can I copy multiple files without prompting?
ftp -i ftpserver

6..How can I allow the local user to login?
In your    /etc/vsftpd/vsftpd.conf
Check “local_enable=YES” 

7..What all are the default port for vsftpd server?
Port numbers  20 & 21

8..How to restart VSFTP server ?
service vsftpd restart
9..What are all the  most common features of vsftpd ?
Virtual IP configurations
Virtual users
Standalone or inetd operation
Powerful per-user configurability
Bandwidth throttling
Per-source-IP configurability
Per-source-IP limits
IPv6
Encryption support through SSL integration

10..Where is the location of the vsftpd file?

 #   /etc/vsftp/vsftpd.conf

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