Author: admin@labtinker.net

Networking
1 May 2021

You Can’t Handle the Data!

Wireshark is a great tool but to my mind it’s only worth using when you’ve exhausted other avenues: firewall or event logs, browser developer tools or even tcpdump. However, there are some occasions when it’s all you have, especially if you don’t have access to intermediate network or filtering devices. I encountered a scenario recently where it was very useful but first I’d like to […]

Personal
3 April 2021

IT Engineers: a spotter’s guide.

I have worked with many IT engineers over the years and they’ve all been delightful, engaging people. They’ve told me about the types of engineers they’ve encoutered and I’ve passed on their descriptions below: The Unengaged Engineer Often an intelligent individual with wide-ranging interests from Sumerian numismatics to hot air ballooning but none whatsoever for doing the job they’ve been hired to do. They will […]

Authentication
6 March 2021

SAML Follow Up

The eagle-eyed amongst you may have noticed I used the certificate vpn.labtinker.net whilst running my Palo on the URL vpn.badtinker.net. The SAML authentication still worked because I guess the relevant public certs are in the metadata so no PKI checking; not in my set up anyway. I did eventually configure the correct certificate but the only difference it made was removing the browser warning I’d […]

Authentication
27 February 2021

Smashing in SAML

My aim in this post is to get administrator access to a Palo Alto firewall using SAML authentication. The theory of this proccess is well-documented. Here is a explanation of it from Palo themselves: https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClVvCAK In summary, SAML allows federated authentication: basically we have a service provider (SP) and an identity provider (IdP) who trust each other. So when a user tries to authenticate to […]

Firewalls
13 December 2020

Checkpoint VPN

I encountered a Checkpoint firewall the other day in the course of my job and realised it had been a few years since I’d worked on one. I think Palo Alto and Fortigate have been stealing Checkpoint’s lunch in the past few years (based on no more than personal experience). At one place I worked which was migrating from Checkpoints to Palo Altos; the former’s […]

DNS
15 November 2020

Barefaced Cheek

I was messing around with various things when I had cause to check the address of this website and found I was getting a different ip address for www.labtinker.net and labtinker.net.  This should not happen because www.labtinker.net has a DNS CNAME record which points to labtinker.net And this in turn points to the ip address of the website: So both these URLs should ultimately point […]

Books
31 October 2020

Wireshark Workbook

With Winter evenings drawing in (in the Northern hemisphere), another lockdown on the cards (everywhere but New Zeland and China), Netflix running out and the liver needing a rest why not augment your familiarity with every networker’s tool of choice: Wireshark? This is a tool I’m sure everyone who’s worked in IT has used at some time in their career to a greater or lesser […]

Authentication
18 October 2020

The Five Trials of Kerberos

I said in my previous post I would discuss how I’d got the Kerberos lab working. The thing is my notes were scrappy and instead of tidying them up it came to me that I’d created a common real-world scenario: a poorly-documented system. Often such systems are encountered by operations staff when said systems are no longer working so let’s break things and see what […]

Authentication
3 October 2020

Who let the dog(s) out?

Kerberos is a venerable and widely used authentication mechanism developed by MIT that underpins Active Directory. A lot of people have posted detailed explanations on how it works like this one: https://www.tarlogic.com/en/blog/how-kerberos-works/ But the labtinker philosophy is to lift this off the page and into a lab so let’s set the stage. There are three actors treading the LAN today: WIN10 is the client, a […]

Personal
20 September 2020

Gather round…

Most commercially available stories we read, hear or view are of exceptional or fantastical events but few of us experience these regularly. In contrast to this, I have been reading ‘The Wrench’ by Primo Levi which celebrates the day-to-day work experiences of a rigger: a man who assembles cranes and bridges. My everyday work is in IT and this is an area that does not […]