Nikto is an Open Source (GPL) web server scanner which scans your webserver against more than 3500 dangerous files/CGIs, outdated version checking, It has a very good plugin support

Buck-Security is a security scanner for Debian and Ubuntu Linux. It helps you to harden your system by running some important security checks. For example, it finds world-writable files and directories, setuid and setgid programs, superuser accounts, and installed attack tool packages.

Computers get faster and smaller every year, but in the case of servers – the building blocks for many modern businesses – the tasks we expect them to perform have increased to match. We so rely on these servers that we increasingly need to monitor what they do, how they do it and when they hit problems.

If Linux is hardly affected by viruses, why do system administrators use anti-virus software on their Linux email servers? Because an anti-virus scanner on a mail server can serve as another level of defense for Microsoft Windows desktop users.

FTP is a file transfer protocol for exchanging files over any TCP/IP based network to manipulate files on another computer on that network regardless of which operating systems are involved (if the computers permit FTP access). There are many existing FTP client and server programs. FTP servers can be set up anywhere between game servers, voice servers, internet hosts, and other physical servers.

The Apache HTTP Server Project is an effort to develop and maintain an open-source HTTP server for modern operating systems including UNIX and Windows NT.

FTP is a file transfer protocol for exchanging files over any TCP/IP based network to manipulate files on another computer on that network regardless of which operating systems are involved (if the computers permit FTP access). There are many existing FTP client and server programs. FTP servers can be set up anywhere between game servers, voice servers, internet hosts, and other physical servers.

Zaragoza, Spain-based eBox Technologies announced the availability of version 1.0 of its Ubuntu Linux-based eBox server distribution.The open source eBox 1.0 features LDAP, DHCP, NTP, DNS, and email servers, among other features, and provides a new development framework for building add-on modules, says the company.

The DNS servers of my ISP is always behaving erratically. The DNS look up times are abysmally large and some times I get an address not found error while browsing. On ubuntu/debian systems the DNS servers are specified in /etc/resolv.conf. I tried to edit /etc/resolv.conf and put open dns servers as default DNS servers.