Mindblown: a blog about philosophy.
-
NAT’s interaction with DNS answers
Recently I was troubleshooting some odd DNS results between 2 customers that have a B2B connection. The DNS record in question existed in the wild on the internet and resolved to 113.129.255.98 (all IP’s have been randomized using https://onlinerandomtools.com/generate-random-ip for anonymity). Customer A resolved to 192.168.20.5 on their end of the link and Customer B…
-
Securing the wired network with 802.1X
This post covers an innovation project I did to secure the wired network at a shared conf center with 802.1X. Every few months we had to disable the wired network in order to prevent non-employees from being able to get online. This was not scalable, was prone to human error, and scheduling confusion. I planned…
-
NTP redesign
This post is about a bug that affected NTP (Network Time Protocol) and our redesign of the environment bypass the issue. In this environment the core Cisco 7604 IOS routers were the NTP stratum 2 servers (x.x.x.123 because fun with port numbers). The IP was an HSRP standby IP. There were several downstream Linux…
-
Blog List
I’ve added a new page of my favorite tech blogs. It’s a page instead of a post as I plan to keep it updated with new blogs and when blogs go inactive. I’ll do the same thing for tools, videos and streams, podcasts, and books. Blog List
-
Guest wifi and branch backup VPN redo
This post is about a situation I ran into a while ago and records my configs and testing for converting from a PBR setup to VRF on a Cisco 881 router with a diagram at the end. Through a combination of configs involving PBR (Policy Based Routing) AKA Source Routing (as opposed to standard Destination…
-
Hello World!
After years of reading other peoples tech blogs i’ve decided to start my own. I’ve delayed doing this because “someone has already written about all the things”. But as Albert Einstein said “If you can’t explain it to a six year old, you don’t understand it yourself.” My planned topics are: Networking/Security mostly focused…
Got any book recommendations?