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Welcome to my personal web site. Here you’ll find useful information and resources that I’ve written over the years.

I am an IT Consultant working in the Auckland, New Zealand, area with a passionate interest in all things relating to Networks and Security. I also do a lot with Linux, Virtualisation, and Cloud systems during my day job. You’ll also find a few odds and ends here relating to other things that I’m doing such as flying small airplanes when time and the weather permit.

Note that I’m still working on some of the content for this site – it’s actually a complete rebuild of the old site which was manually coded HTML. I’m still importing stuff from the old site such as the Logsurfer info and the aviation check lists. Please bear with me for the next couple of weeks – or let me know if there’s something missing that you’re looking for.

Please note that all comments are currently being moderated due to the number of spam comments coming in. If you post a comment please wait a day or so for me to approve it.

 

 

Permanent link to this article: https://www.crypt.gen.nz/

Using Ansible for Automated Network Testing

The problem with making changes to any decent-sized network, which is running a routing protocol such as OSPF, is that in order to fully verify the change you will need to log into every device in the network and verify that your change has worked. This post shows how Ansible can be used to perform …

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ciscoios-acl – A Fail2ban Module for Managing Cisco IOS ACLs

I’ve been using fail2ban to protect a number of services from external attacks. The software works well, but what I wanted to do is to have fail2ban update an ACL on a Cisco IOS router rather then the IPtables on the host itself. Here’s the code and some tips on setting it up.

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Blanket Box

I made a pair of these blanket boxes a few years ago, and finally got around to taking photos and publishing the result.

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Dual Stack Policy Rules on Cisco IOS Zone-Based Firewall

The Cisco Zone-based firewall was derived from the old “firewall feature set” and allows the administrator to define firewall rules based on zones, where each zone may contain one or more logical interfaces. Using Cisco’s zone-based firewall isn’t as easy as many other solutions (e.g. Juniper SRX, Cisco ASA), and recently I needed to configure …

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New Zealand Wood Pigeon – Kereru

Every year these large pigeons come and eat the new shoots from the trees around our house. Here’s a picture of a recent visitor.

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Restricting Management Access to Fortigate Firewalls

Sometimes it’s just unavoidable that you need to do in-band management of firewalls. This is particularly the case if the firewall is hosted externally – such as within AWS. Here’s a quick recipe on restricting management access to the Fortigate firewall.

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Juniper OSPF and Unexpected Features

I had an interesting situation in a lab environment the other day. It seems Juniper has been tweaking how OSPF works with their routers with some interesting consequences.

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Cisco ASA 5505 – Dual Internet Connections with a Base Licence

The client’s requirements were simple: they had an existing Cisco ASA 5505 with a base and unlimited users licence connected to the Internet with a PPPoE interface over ADSL. They wanted to add more bandwidth and redundancy so decided to add an additional 100mbps fibre link. Is it possible? Read on …

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