While working to verify some packages in Ubuntu 12.04 had backport patches installed properly I needed to list installed package versions. To do this you can install a package called apt-show-versions which will allow you to list all installed packages and their versions with ease. This likely works on most Ubuntu versions but was tested on Ubuntu 12.04 also know as Precise Pangolin and Ubuntu 12.10 also known as Quantal Quetzal. Follow the instructions below to install apt-show-versions and then list all installed packages and their versions.
The arping application is a simple command that will allow you to ping devices by hostname, IP address, or MAC address. The unfortunate part is that most device will not respond to the arp requests, which are directed broadcast ICMP echo requests, though there are some out there that do. I go into more detail below regarding pinging via MAC address by providing an example of the typical output, example output when a MAC address responds to the ICMP echo requests, and details about how to configure hosts to respond to these ICMP echo requests. I also show a couple of the switches available with arping and provide examples of using arping to ping devices by IP and host.
I was working with a coworker today to setup a new Redmine server running on top of Ubunut 12.04 and one of the steps we completed in the process was setting up LDAP authentication in Redmine. Setting up LDAP authentication in Redmine requires the server running Redmine to be joined to the Windows Active Directory domain so I needed a quick way to auth Linux on Active Directory. I have used Centrify in the past and remember it being really easy to setup authentication from any form of Linux to a Windows domain and again it did not disappoint. Follow the directions below to join a Linux server to Active Directory using Centrify.
The dnsenum.pl Perl script as described in its Perl documentation is a multithreaded script to enumerate information on a domain and to discover non-contiguous IP blocks. So the gist of dnsenum is to gather information about a specific domain using various sources. Information gathered about a domain includes sub domains, associated IP ranges, name servers, mx records, reverse DNS records, hostname IP addresses, and potential vulnerabilities via zone transfers. Below we go into detail regarding the switches available with dnsenum as well as what the command returns by default without and CLI switches.
While working on an upcoming article for QD I ran into an issue with the dnsenum.pl Perl script. I followed the process of installing the optional Perl modules and when I went back to test dnsenum it would no longer return any IP addresses. Instead of dnsenum returning actual IP addresses it was returning odd characters. It turns out there is some form of conflict between dnsenum.pl and the Net::DNS Perl module. Below I describe the dnsenum issue in more detail and provide a work around by manually downgrading the Net::DNS Perl module by hand.