Getting started with Ansible

The easiest way to describe Ansible is that it’s a simple but powerful it-automation tool. In the words of its creator Michael DeHaan “I wanted a tool that I could not use for 6 months, come back later, and still remember how it worked.” and it really feels like riding a bike. Even years from now when I take a look at an Ansible Playbook I’m sure I will immediately see what it does. Playbooks, which allows you to run several tasks together, are writting in YAML making them easy to read.

This guide is too short to teach you everything about Ansible. Instead the aim is to give you an idea of how you can use Ansible, and how it can help you manage your IT environment. Even if you don’t end up using Ansible, learning tools like it as Chef or Puppet can help you to think differently about how you operate your network.

Getting started with Ansible

The easiest way to describe Ansible is that it’s a simple but powerful it-automation tool. In the words of its creator Michael DeHaan “I wanted a tool that I could not use for 6 months, come back later, and still remember how it worked.” and it really feels like riding a bike. Even years from now when I take a look at an Ansible Playbook I’m sure I will immediately see what it does. Playbooks, which allows you to run several tasks together, are writting in YAML making them easy to read.

This guide is too short to teach you everything about Ansible. Instead the aim is to give you an idea of how you can use Ansible, and how it can help you manage your IT environment. Even if you don’t end up using Ansible, learning tools like it as Chef or Puppet can help you to think differently about how you operate your network.
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Check Cisco ASA Connections with Nagios

Once you’ve setup your Cisco ASA, you will want to monitor it to ensure that it’s operating normally. The plugin nm_check_asa_connections for Nagios, and compatible products, can warn your if the number of current connections gets too high. A very high connection count might indicate that there’s an attack under way on one of your servers, you have some hosts on your inside which are part of a botnet and is attacking someone else, or perhaps you’re just about to grow out of your current firewall and need an upgrade to a more powerful box.

Check Cisco ASA Connections with Nagios

Once you’ve setup your Cisco ASA, you will want to monitor it to ensure that it’s operating normally. The plugin nm_check_asa_connections for Nagios, and compatible products, can warn your if the number of current connections gets too high. A very high connection count might indicate that there’s an attack under way on one of your servers, you have some hosts on your inside which are part of a botnet and is attacking someone else, or perhaps you’re just about to grow out of your current firewall and need an upgrade to a more powerful box.
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Dynamically monitor interfaces with Nagios

When you’re setting up your monitoring configuration for Nagios or compatible software it can be a hassle to decide which interfaces you actually want to monitor. Well rather how to monitor those interfaces. The nm_check_admin_up_oper_down plugin (part of Nelmon) checks the configuration of your network devices and reports a problem if you’ve indicated that the interface should be up.

Dynamically monitor interfaces with Nagios

When you’re setting up your monitoring configuration for Nagios or compatible software it can be a hassle to decide which interfaces you actually want to monitor. Well rather how to monitor those interfaces. The nm_check_admin_up_oper_down plugin (part of Nelmon) checks the configuration of your network devices and reports a problem if you’ve indicated that the interface should be up.
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The onePK office prank

You know those times when you paste innocuous config to a router and it just freezes up on you? Even if you know you’ve done nothing wrong it can be a few scary seconds until the router starts to respond again. While reading up on onePK I was trying to come up with a use case. Though I eventually thought about some other things that would actually be useful. The very first thing that came to mind was something to test just for fun.

The prank

Picture this; You ask a co-worker to login to a router and shutdown an interface which won’t be used anymore. Your colleague logs into the device and disables the interface and the session hangs. Only it doesn’t just hang, it’s dead and apparently your colleague can’t ping the device now. At this point it can be a good idea to ask your co-worker about what exactly he changed.

The onePK office prank

You know those times when you paste innocuous config to a router and it just freezes up on you? Even if you know you’ve done nothing wrong it can be a few scary seconds until the router starts to respond again. While reading up on onePK I was trying to come up with a use case. Though I eventually thought about some other things that would actually be useful. The very first thing that came to mind was something to test just for fun.

The prank

Picture this; You ask a co-worker to login to a router and shutdown an interface which won’t be used anymore. Your colleague logs into the device and disables the interface and the session hangs. Only it doesn’t just hang, it’s dead and apparently your colleague can’t ping the device now. At this point it can be a good idea to ask your co-worker about what exactly he changed.

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Getting started with Cisco ASA

Even with people who work in networking, as soon as you say the word “firewall” a lot of people tend to stare at that far away place that only exists in their minds. I think some of this comes from the fact that “it’s not a router”. Another reason is that people just haven’t taken the time to get familiar with firewalls. The ASA is Ciscos firewall or VPN device. Though the ASA can do a lot of things, in this post I will cover the basics such as how you set it up and connect the device to the Internet.
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SYDI-Server 2.4

It’s now over 10 years since I released the first version of SYDI-Server, back in August 2004. During the first years I wrote quite a bit of code and kept adding features to the different scripts. However, the last version SYDI-Server 2.3 was released in 2009. So one could say that development has slowed down a bit. However even today it gets a few hundred downloads every week. Even today I keep getting emails from people who’ve just found SYDI for the first time and are loving it. Continue reading

Gathering Ansible facts from network devices using SNMP

At times when I look at the tools available for server admins today I long for the times when I didn’t work in networking. Sure we can use tools like Puppet and Ansible for networking too. However the tools are made for servers. Of course there are tie-ins into network automation, but the functionality is rudimentary at best. The current problem as I see it is the lack of decent APIs, granted some vendors are better than others. And I haven’t had the pleasure of working with those who understand XML. Sometime in a not too distant future when we have flying skateboards, SDN and nano bots these problems will disappear, but we’re not there yet. Before I take a deep dive to see what’s actually possible to do with onePK, OpenDaylight and all that good stuff I wanted to see how much is possible to do today. So this post is about Ansible which is really simple to learn and SNMP, where one of the words in the acronym is “simple”. It should be a perfect match, right?
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