SysteMajik Consulting

Category: System Administration

Posts related to system administration. Mostly applicable to Linux distributions, mostly Ubuntu/Debian and OpenWrt; see tags.

  • Firewalling Google Chat and Skype

    To enable for Internet chat I set up Google Chat and Skype.  My firewall rules have been extremely restrictive with only known and approved services allowed to connect.  Google Chat installed with no noticeable impact to the firewall. Things did not go so well with Skype.

    The installation of Skype resulted in lots of warnings on the firewall.  Outgoing tests worked with only port 80 and 443 open.  Skype’s peer-to-peer approach  requires at least one port be opened incoming and and a large range of ports outgoing.  They specify all ports over 1024 should be open.  Their preferred mode seems to be to use uPnP to dynamically modify the firewall.   They do allow you to attempt to set  fixed incoming port which is also used for some outgoing UDP traffic.

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  • Setting up Squid Proxy on Ubuntu

    Squid is a proxy service for HTTP and other requests. This article covers installing it and configuring it to run on Ubuntu as a transparent proxy. This documentation includes configuring Web Proxy Auto-Discovery (WPAD) via DHCP and DNS.

    I run a heterogeneous configuration. This provided a number of challenges as various implementations of WPAD were encountered. Each seems to require something different. The final configuration works for Ubuntu, Windows X/P, and Windows Vista. Both Internet Explorer and Firefox configured correctly.

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  • Connecting a Palm via USB

    The computer to which I had been synchronizing my Palm Tungsten E died a while ago. I explored the two options for connecting to my Ubuntu system using a USB cable. The fastest is to use a direct USB connection. However, I wanted to ensure I could synchronize over a network connection. I also configured and tested setting up a PPP connection over USB. (more…)

  • Analog with Report Magic and Logwrangler

    I am now using Report Magic for Analog with my Analog installation.  My last attempt had failed miserably, but this time it went extremely well.  I found Logwrangler which does a lot of the work.  I encountered an incompatibility between Report Magic and an updated graphics library.  Once the patch was applied the program ran well.  All that was left was tuning the report layout and the interaction with Logwrangler. (more…)

  • Analog for Multiple Sites

    Analog is a fast and flexible web log analysis tool.  Its configuration can consist of several files nested using include statements.  This allows common configuration items to be grouped in separate files.  The minimal site specific configuration items can be contained in small include files.  Similarly, time period specific include files allow for reports by time period to be easily configured.  Each report then requires a configuration file, which includes a few other files.

    I have reviewed and updated my previous documentation for analog.  This site is hosted on a new server, and I needed to setup analog for the new server.  I also made changes to the list of virtual sites being hosted.  I generate report sets for each site as well as an overview report for all sites.  Each report set includes reports for covering the latest week, month, and year of data.  (more…)

  • Monitoring with Munin

    Munin is a system monitoring program designed to capture and graph performance statistics with minimal configuration. It is significantly easier to configure than MRTG and has a wide variety of plugins.  The Ubuntu (Debian) installer will setup a reasonable configuration on installation.  It requires one server, and a client daemon on all monitored servers including the server. Scalability to large (campus) environments has been reported to be an issue (more…)

  • Installing WordPress on Ubuntu

    WordPress is available as a packaged application for Ubuntu.  However it requires a bit of post installation configuration. The installation will install the apache2 multi-user server if no server is installed. I modified the installation to run over top of an existing site.  The default installation creates directories under /var/www, which I move to /srv. (more…)

  • Setting up Windows

    The following guide is intended to help install Windows on system in a secure manner.  The steps here are intended to limit the exposure of the system to malware during installation.  However, it does not guarantee that malware will not infect the system.  There are many known vectors used by malware, some of which are known to bypass the following steps. (more…)

  • OpenWRT and Ubuntu dnmasq setup

    Now I have replaced my old firewall with OpenWRT, I needed to enhance the configuration of dnsmasq to support the network.  The old Ubunutu based firewall was already running dnsmasq, as does the DNS server on the LAN.

    I run a mixed network with wired and wireless clients on separate address ranges. DHCP services are provided by the OpenWRT router. An Ubuntu server is the primary DNS server for the wired network. (more…)

  • OpenWRT syslog-ng Installation

    When I went to process my remote firewall log output from OpenWRT, I noticed that the entries were truncated.  A quick check with tcpdump indicated that the syslog packets were truncated to 256 characters.  As syslogd and klogd are both provided by BusyBox, I decided to replace them both.  The obvious solution was to replace them with syslog-ng.  opkg indicated that it was available, so installation was simple.

    Unfortunately, configuration is not yet automated.   A default configuration file is provided in /etc/syslog-ng.   This simply logs to /var/log/messages.  It also assumes that klogd is active.  After some research and experimentation, I came up with a configuration. It can provide a local log in /var/log/messages. More importantly it provides complete firewall log entries to the remote server. (more…)