VSFTPD supports virtual users with PAM (pluggable authentication modules). A virtual user is a user login which does not exist as a real login on the system in /etc/passwd and /etc/shadow file. Virtual users can therefore be more secure than real users, because a compromised account can only use the FTP server but cannot login to system to use other services such as ssh or smtp.
This example shows how you might set up a large internet facing FTP site for distributing file or software updates. The emphasis will be on security and performance. VSFTPD will make sure only world-readable files and directories are served to the world via anonymous / ftp account. You force to originates FTP port connections from a secure port – so users on the FTP server cannot try and fake file content. You will hide the FTP server user IDs and just display ftp in directory listings. This is also a performance boost. Set a 40000-60000 port range for passive connections. This will help firewall setup.
vsftpd FTP server supports secure connections via SSL / TLS, same encryption used with online banking and shopping. This applies to the control connection (including login) and also data connections. You will need a ftp client with SSL support too.
The Courier mail server is a mail transfer agent (MTA) server that provides ESMTP, IMAP, POP3, webmail, and mailing list services with individual components. But, it is best known for its IMAP / IMAPs and POP3 / POP3s (secure version) server component.
Courier can provides support for both regular UNIX operating system account (stored in /etc/passwd) and virtual mail account managed by third party backends such as OpenLDAP, MySQL and so on.
In this quick tutorial, you will learn about installing Courier IMAP SSL digital certificate.
I’ve already written about Linux process accounting under Linux ( see how to keep a detailed audit trail of what’s being done on your Linux systems). You can easily setup process accounting under FreeBSD. This tutorial expalins how to enable and utilizing FreeBSD process accounting including many other useful options are explained to keep track of system resources used, and their allocation among users.
Virtualization is the latest buzz word. You may wonder computers are getting cheaper every day, why should I care and why should I use virtualization? Virtualization is a broad term that refers to the abstraction of computer resources such as:
- Platform Virtualization
- Resource Virtualization
- Storage Virtualization
- Network Virtualization
- Desktop Virtualization
This article describes why you need virtualization and list commonly used FOSS and proprietary Linux virtualization software.