Sometimes it happens, for some reason, you need to move your VMWare hosts to a new subnet. Let’s talk about what you might want to consider and how to make the process as smooth as possible.

OSPF is mostly used between a Core switch and downstream OSPF enabled devices like distribution switches, firewalls, etc. If the downstream device is connected via link aggregation to a Nexus vPC pair and vPC peer-gateway is configured, you will encounter OSPF adjacency flaps. This will not be noticed unless the OSPF adjacencies are monitored or debugged, so most engineers are not even aware that...

You know how to whistle, don’t you? Just put your lips together and blow. Well installing WSL is nearly as easy and can up your efficiency and expand your toolset.

Passwords, or In-The-Past Words?

Are passwords a thing of the past? Well to be honest, no not yet they aren’t, but there seems to be a widespread initiative to cram them into a time capsule, move into the future, and forget about them altogether. From post-it notes to password managers, to any of the other tools or tricks that people use to remember them, passwords are renowned for being a weak...

If you aren’t already using file checksums, why not? It’s a REALLY good idea for any file you download over the internet. It could also be a good idea for a file you may want to ensure stays unchanged on your own network. File checksums are a vital tool for ensuring the integrity and authenticity of files. They serve as digital fingerprints, allowing you to verify whether a file has been tampered...

Say hello to Cisco’s RADkit

How would you like a tool that can save you time with TAC cases and gives you an avenue of automation and time savings for your entire Cisco environment? If that sounds good, you should give RADKit a look.

So, you’ve verified your firewall appliance is allowing your application traffic, you’ve ensured your routers are getting the traffic where it needs to go, and your access control lists on your switches are perfect. A packet cap on your switch shows the traffic getting to your Windows server. Why isn’t it working? I’ve run into the Windows server itself blocking traffic destined to its own...

Introduction

This will be the final installment in this NSLOOKUP Primer series. Last time, I talked about MX & SPF TXT records here, but I didn’t touch on DMARC & DKIM TXT records which are also highly encouraged to help add additional layers of security to your email domain.

In my last nslookup blog, I talked about some basic DNS troubleshooting. If you missed it, here’s the link. This time, I wanted to dive in to how I use nslookup for email info gathering and troubleshooting.

So there you are in front of your computer, you know you have internet access, you can ping 8.8.8.8, but your browser isn’t working, and when you try to ping google.com, the name is unable to resolve. You think to yourself “If only I had saved that blog article about nslookup locally, so I didn’t have to depend on the internet to get all that great info!”.