Archive for the ‘Linux’ Category

VMWare Server Tips

VMWare Server on Linux (VMWare Server 1.04 on Ubuntu 7.10 Server)

– Physical Network Interfaces that will only be used by VMWare Guests:

Even though you may have a physical interface that a Host will not use, you need to set-it-up in /etc/network/interfaces. This will activate the network interface for the Host, which will only then allow the Guest system to utilize it. I am sure there may be a more elegant and secure way to accomplish this – I just haven’t had the time to do it myself. So, as a work around, I assign a static IP address, with a 32-bit subnet mask. This activates the interface, without providing a IP capabilities on the network.

There is probably a better/ more secure way to do this… let me know.

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My toolbox – an incomplete list:

MTR – Link Diagnostics
IPerf – bandwidth test
TCPTrack – track tcp connections per interface

An indespensbile trouble shooting tool is MTR. It is already a part of my favorite distro, Ubuntu. It combines the functions of ping and traceroute, and the info provided is excellent for diagnostics. More at: http://www.bitwizard.nl/mtr/

Just use it in place of ‘ping’. For example:


This will update your terminal display with:

– Packet Loss %

– Packets Sent

– Ping, Last Response Time

– Ping, Average Response Time

– Ping, Best Response Time

– Ping, Worst Response Tim

and my favorite

– Ping, Standard Deviation


The gold standard for bandwidth testing. In Ubuntu:

sudo apt-get install iperf

To use, you need one session running as the server, and another (or several) as the client.

A quick example:


iperf -s -D

this command will run the server


iperf -c -r -t 30 -P 3

this will connect to a server at IP, and perform a two-way test for 30 seconds each. The -P 3 is interesting, as it will run 3 parallel processes to get full bandwidth results. This is especially useful on a Windows system, and a single connection test won’t be able to pump out the full bandwidth capabilities.

The results are quite useful.


Quick reference to active connects on an interface.  Excellent on a proxy/ router to monitor who might be using to much traffic

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Check out http://www.lm-sensors.org  an open source project for embedded “sensors” for your Linux system.

I needed an easy way to check the CPU temperature for my new PC from the command line.  This is yet another great example of what open source has to offer.

On my Ubuntu 7.10 server, it was too easy:

sudo apt-get install lm-sensors

sudo sensors-detect

This will test your system to see which sensors should be installed.  Near the end, allow it to auto-add the kernel modules for you (make a note, in case you want to yank them later – for me, once I am done with the testing, I may remove them.)

Reboot your system

Once rebooted, type:


This gave me what I was looking for – CPU temp.  And a bonus – fan RPM.

I am sure there are many other uses for this – I have just scratched the surface.

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I’ve been in the IT industry for almost 15 years, and worked with both large and small companies. I have never had an opportunity to work with the BGP protocol, until now. My experience with it has been fun (for a nerd), and I have now expanded my networking knowledge, just a little bit, so I want to share with you what I have found. I am by no means a BGP expert now, but can confidently understand and configure a somewhat complex arrangement with it.

As with all things for me, it would have helped immensely if there was a step-by-step example of how to complete my project. I learn by example, and can understand something if I can see the completed work first. So, I will provide that for you here.

Of course, I will be using open source tools – old hardware on Ubuntu Server 7.10, with Quagga. Clean, simple, stable, reliable.

Details to follow soon…

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Quick Tips on Networking with Linux

Sometimes you may boot your computer and find that the network is not up.  You check the built in network tools, and can’t easily see what the problem is – time to drop to the command prompt to make some changes.  Here are some tips:

Check you current settings:


Don’t see your network interface(s) listed?  You may need to manually configure them.  Try this:

ifconfig -a

to show you all of your interfaces.  You are likely looking for ethx, where x is a number for your interface.

Now you’ll need to edit the network config file:

cd /etc/network
sudo vi interfaces

To add DHCP to a network interface, your config file should look like this (for eth1, for example):

auto eth1
iface eth1 inet dhcp

That’s the bare-bones basics.  I’ll add more later.

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I’ve tried to separate the chaff from the wheat. Here is a list of application I’ve found to be the best (my opinion) in their particular areas.  Suggestions for additional applications/ categories are always appreciated.

Outlook replacement:
Still looking. Evolution, Kontact, and Thunderbird (and its variants) don’t come close to the speed and usability of Outlook yet. I’d like to see something integrated/ included in the OpenOffice system that could better compete with Outlook in this respect
UPDATE 11.29.07:
Evolution is the winner. I have worked around the issues, and will write a new article about it soon. Take a look at the latest Evolution http://www.gnome.org/projects/evolution/

Office replacement:
OpenOffice.org. I don’t even use MSOffice (other than Outlook I use Evolution now) anymore. OpenOffice has come a long way – and most distributions include it. If you are using Ubuntu (I recommend it) than you have it already.

Firefox, Opera – Opera is slicker, Firefox is GPL. You probably already have Firefox.

Music Player:
Amarok – hands down. Works with iPod, among many other useful features (I do not own, or want to own, an iPod, BTW)

TV, Multimedia player for home entertainment (Tivo-ish):
Myth TV – Not too difficult to setup. Works very well with standard cable, DVDs, and multi-location systems. I am working on setting up a single back end server in my office, with several smaller front-end PCs for general TV viewing in the living room and bedroom. You can add your DVDs to your server’s library on disk, so they can easily be selected.
LinuxMCE – Includes MythTV, but then takes it up a notch with home security, presence awareness, and a bunch of other features. Looks like it has special hardware requirements, and a lot of patience… worth taking a look.

IT Backoffice (Server) Apps:

Small Office Server:
EBox – Simple to install and manage, for the inexperienced (and time constrained). Quick setup. Probably would be difficult to expand to your own solution (such as, if you wanted to open up the LDAP server, or integrate with a different e-mail package. Overall though, covers everything you need for home or small office.

Website/ CMS:
Joomla (I looked at Mambo, of which Joomla forked from a while back – I prefer Joomla’s AJAX, plug-ins, etc.  They are both still very similar, however.

EGroupware – Nice Intranet server, with web mail capabilities, among many other functions. Probably works well with EBox (above) – I’ll let you know when I am finished. UPDATE: Not working well with E-box yet…

Exchange Server replacement:
Scalix (better than Zimbra, my 2 cents) – drop in replacement for Exchange in organizations needing to replace Exchange; the purchased edition of Scalix is the only one that fits the bill. The Open Source Community Edition is nice to, but is limited to 25 premium users (Exchange MAPI users). If you don’t absolutely have to use MAPI for Outlook, I’d go with an alternative for sharing Calenders, Tasks, and Contacts. When I settle on one, I’ll let you know.

Kolab – still looking at this one, but right now it is difficult to setup and get started.

Courier, Postfix, MySQL, RoundCube – this is what I am currently using.  Standard, solid, works.

Firewall/ Routing:
Monowall, PFSense (Derives from Monowall) – I use PFSense myself. Easy to setup and configure, lots of features, low requirements.
IPCop – tons of features, powerful, in wide use. Probably more for larger organizations.
Vyatta – Heavy duty routing. One of those partially open-source projects. I looked at it initially, but went with Quagga, which is a little more hard-core, and is working great.
Linux w/ Zebra – Zebra hasn’t been touched in a while, instead use:
Quagga on Linux – I am using Quagga for BGP on high-end Internet connection (w/ OSPF).  Fast, technical setup, but works well when serious routing is needed – see my other article on this(coming soon).
Shorewall/ IPTables

These are packaged products (above). However, it can be useful/ rewarding to put together the pieces yourself. For example, instead of IPCop, setup you own Shorewall firewall, SpamAssasin, ClamAV, HTTP/FPT/SMTP Proxy, etc…

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Now that Ubuntu is installed the fun begins. First things first:

– Install all available updates
– Reboot if necessary
– Add medibuntu repository (check your local laws for usability)
– Install VMWare Server for virtualization

To install apps from the repositories (that is this great big pile of software that Ubuntu maintains for you to easily access over the Internet) you can use the Synaptic Package Manager (Menu:System-Administration). I personally prefer to use the command line where possible, as it makes it easier (for me) to make a list of what I will do.

To get started, let’s update the system: Menu:System-Administration-Update Manager. Note: You can’t have Synaptic and Update Manager open at the same time. The Update Manager is basically a subset of Synaptic – it just checks for updates for packages you already have installed. Also, after login (with an Internet connection) you will see a pop-up dialog in the top right menu of your Desktop letting you know if there are updates available.

Moving on… check for updates, install any available, and reboot if required.

Step 5 will be on multimedia configuration

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