Building a Centos Server Image

System Build Options

This is the first of what will be a number of posts on building out parts of a basic mission network.  This network will be based on Centos 7 (Linux), with an IPA server (Linux version of Active Directory), have a local patching server, and a number of there features.  Today’s article will focus entirely on the basic build of a Centos 7.0 system and will serve as the base system for all of the other lessons in the future

Getting from A to Z Part 2 (Troubleshooting Layer 3)

Troubleshooting

By and large I personally think that most of us are much more comfortable with layer three than any other layer in the OSI model. We deal with it each and every day. We have a number of tools at our disposal which make it very easy for us to see if/when it’s working and just how the data is traveling. To start with though, we have to know just how things are supposed to work.

Getting from A to Z

Troubleshooting

When I entered the Army in July 1999, I came in as 31F (switch operator). Anyone who worked with MSE will remember that it had almost absolutely no data capabilities, but also that it was extremely easy to troubleshoot. Signal flow for MSE was pretty darn easy to understand. If you understood the idea of how the system worked, the signal flow was easy to follow. With the introduction of JNN and IP data networks to tactical communications, logical and physical said “It’s been fun” and headed their separate ways leaving our operators and even ourselves busy scratching our heads wondering how the hell it all worked.

Cisco Discovery Protocol (CDP)

Show CDP Neighbor

When there is a problem with the network, time matters. We need to be able to quickly move from device to device in order to identify and rectify the problem. In order for this to occur, we have to know where to go to next, and how to get there.

What Time Is It?

WIN-T NTP Architecture

Let me give you a scenario. You are having some problems on the network that are spread across several devices. You go into the log file of each device and see a bunch of messages with a mix-match of various times that mean absolutely nothing to you. In short, you have no idea what is going on with your network.

Shapes for Visio Diagrams

Network Diagram

As I’ve stated in previous posts, an accurate network diagram can be really important when it comes to troubleshooting and managing the network. In order for a diagram to be of use to us, we have to maintain it which means that we update it every time the network changes. Another important part of a network diagram, is that it uses recognized symbols to depict what it is trying to show. ADRP 1-02 (Terms and Military Symbols) does a great job of providing us with standardized symbols for units of various sizes, terrain features, and even many pieces of equipment, but almost nothing to symbolize current day military communications equipment.

5 Router Commands That Saved My Life

Cisco Tattoo

We have all learned an important lesson in life the hard way. When it comes to working on the router or switch, there is often a couple of commands that you discovered after beating your head against the wall for a while that if you had known about them earlier, would have made your life so much easier. These are those commands for me.

But they didn’t teach me that in WOBC! – Comments in configs

Config Comments

There are a few things that are in WIN-T that are not explained in school. You either find yourself figuring it out or being told by another Warrant. How many of you have noticed that there are configurations available for all your equipment in TXT format? How many of you use them to blow in configurations when replacing gear from your spares? How many of you have read all the comments?