VMware vSphere and your firewall

Posted on July 14, 2011 by Lammert Hellinga

As some of you may know, I’ve started working for my new employer last month.

I’m now busy with my so called Masterclass and for that I’m attending a lot of courses. A couple of weeks ago I attended a five-day VMware vSphere course and in a while I will take an exam and try to get my VCP4 certification.

At home I’ve created a labsetup so I can fiddle around with ESXi, vCenter server, etc. without breaking any setups. Today I was trying to get a connection to my vCenter server from work but that involves opening a couple of ports in your firewall or, in my case, tunneling a few towards my home. At first it was unclear to me which ports should and shouldn’t be opened. I found this page which provides this pdf. This is a great diagram mentioning all ports for all connections typically used in your vSphere environment.

I found this to be very usefull and therefore like to share it with you as well.

 

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JSONBOT plugin

Posted on May 16, 2011 by Lammert Hellinga

Afternoon y’all!

Last weekend I decided to give observium a try. Observium is a network monitoring system and fully snmp-based. There are also alternatives like Zabbix and/or Nagios but Observium differs that it’s very very easy to set-up.

I’ve spent like half-an hour installing observium on a clean debian server and after those 30 minutes it was already graphing 3 devices in my network. I’ve spent a couple of hours after that toying around, discovering what’s possible and what not.

Something observium does is when it discovers a problem, for example a device that got disconnected, it sends an e-mail to the snmp-syscontact (or if overridden another email address).

I usually also have an irc window open when I’m sitting behind my computer like many of you I suppose. And I almost immediately had the wish that the irc-bot (jsonbot) that I have running would be connected somehow to observium and inform me of those messages. A couple of friends also use observium (one of them has been pushing me around a lot when o when I would start using observium :P ) and they also liked the idea.
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Configuring Site-2-Site VPN using IPSec

Posted on May 5, 2011 by Lammert Hellinga

This is the first out of a series of 3 posts I’m about to make. These posts will cover setting up an Site-2-Site IPSec VPN tunnel, GRE tunneling and iBGP. This post will cover setting up an Site-2-Site IPSec VPN tunnel between a Cisco 2600 Series router and a Debian box running ipsec-tools and racoon.

As I’ve mentioned before I’ve wanted to create a VPN setup between my home and my VPS’es. Not because it’s necessary but just because it’s possible and I learn something from it.

A couple of weeks ago I finally started this project, reading documentation and try to get it working. I started off creating a suitable test-setup here at my house. I booted one of my Cisco 2651XM’s with a IOS 12.4 image and gave it a clean configuration. 1 ethernet port connected to my home-network so I had a way in and the other connected to a dedicated server which I provided with a fresh Debian install just for this exercise.

With this test-setup I had clean configs, no software or other things that might interrupt this exercise and if I somehow created a big mess it wouldn’t interfere with my production setup.

So with all things ready it’s time to start configuring everything. Before I start pasting and explaining my configs let me remind you of one thing. Everything i did is a way of doing it. It’s not the right way, it’s not the wrong way, it’s just the way I did it and there are numerous other ways of accomplishing the same result.
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Posted in Networking | 1 Comment

Updates

Posted on October 19, 2010 by Lammert Hellinga

This evening the brand new website of my employer went live (click here if you’re interested).

I thought to be nice to perform an update on my personal site, which you’re reading right now, obviously :P

What is updated you might ask… well: i’ve updated my “About Me” page with my newly created linkedIn profile. I’ve added the “follow me” button on the left of this site with links to my twitter and my linkedIn profiles. And i added this post :D

So what’s been happening lately in my life… about 2 months ago i “finally” graduated i am now “Bachelor of Engineering”. In less than a week i’ve got a full-time job at my employer. I must say it’s a lot of weight of off my shoulders, no fuss about graduating anymore. Just working full-time and having fun in my weekends, i’m loving it. Continue reading →

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Python and net-snmp

Posted on July 8, 2010 by Lammert Hellinga

Some of you may know that i have a 19″ rack at home with some interesting hardware in it. Some of this hardware also provides a couple of hundreds of gigabytes of storage. But that system takes about 3 maybe 4 amps when it’s idling. Taken into account that 1 amp 24/7 costs me about 20 euros per month. So you can imagine that i don’t have all my equipment running 24/7.

Once in a while i use this system to put some files onto it and then i turn it off again. To be able to also do this remote i’ve bought myself an APC PDU (model AP9212) a couple of months ago. Since that time i always had an idea to automate a backup job which would perform the following steps for me:

  1. Turn on my storage system
  2. Mount the backup share
  3. Transfer the backup onto the share
  4. Unmount the backup share
  5. Send a shutdown command to my storage system
  6. Turn of my storage system

The day before yesterday i finally put my hands on this idea and started looking how i could get and set data to and from my PDU using SNMP. A while ago i already figured out the specific OID’s needed for this job.
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Posted in Networking, Programming | Tagged , | 3 Comments

Blog Live

Posted on July 7, 2010 by Lammert Hellinga

Hi,

I’ve just installed my new blog, soon i will add some posts with things that i come across and/or keep me busy during my daily life :)

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