The purpose of this post is to introduce a user to the nmap command line tool to scan a host and/or network, so to find out the possible vulnerable points in the hosts. You will also learn how to use Nmap for offensive and defensive purposes.
via Top 30 Nmap Command Examples For Sys/Network Admins.
Nmap can be very useful which is why I have a link to it in the Tools section on this page.
Say hello to agedu tool (pronounced as ‘age dee you’) – it scans a directory tree and produces reports about how much disk space is used in each directory and subdirectory, and also how that usage of disk space corresponds to files with last-access times a long time ago. In other words, this command might help you to free up disk space.
via agedu: Unix / Linux Command For Tracking Down Wasted Disk Space.
Can I access agedu reports using terminal mode?
Type the following command (replace /home/wwwroot with actual path):
$ agedu -t /home/wwwroot
This Linux based firewall is controlled by the program called iptables to handles filtering for IPv4, and ip6tables handles filtering for IPv6. I strongly recommend that you first read our quick tutorial that explains how to configure a host-based firewall called Netfilter (iptables) under CentOS / RHEL / Fedora / Redhat Enterprise Linux. This post list most common iptables solutions required by a new Linux user to secure his or her Linux operating system from intruders.
strace is a useful diagnostic, instructional, and debugging tool. It can save lots of headache. System administrators, diagnosticians and trouble-shooters will find it invaluable for solving problems with programs for which the source is not readily available since they do not need to be recompiled in order to trace them. This is also useful to submit bug reports to open source developers.
via Debugging Tip: Trace the Process and See What It is Doing with strace.
Run strace against /bin/foo and capture its output to a text file in output.txt:
$ strace -o output.txt /bin/foo
Usermin is a web-based interface for webmail, password changing, mail filters, fetchmail and much more. It is designed for use by regular non-root users on a Unix system, and limits them to tasks that they would be able to perform if logged in via SSH or at the console. See the standard modules page for a list of all the functions built into Usermin.
via Webmin.
Cobbler is a Linux installation server that allows for rapid setup of network installation environments. It glues together and automates many associated Linux tasks so you do not have to hop between lots of various commands and applications when rolling out new systems, and, in some cases, changing existing ones.
With a simple series of commands, network installs can be configured for PXE, reinstallations, media-based net-installs, and virtualized installs (supporting Xen, qemu, KVM, and some variants of VMware). Cobbler uses a helper program called ‘koan’ (which interacts with Cobbler) for reinstallation and virtualization support.
via cobbler.