Windows 10 USB-to-Serial adapter Woes…

Cisco, Microsoft, Windows
About 2 months ago, I had to go to a new customer site that was down and diagnose a problem.  Easy, I've done this a thousand times over the past 15 years...  Device not recognized. My USB-to-Serial adapter (no name brand off of Amazon) wasn't working.  Code 10 Error. I'm documenting this because, as infrequently as I actually use a console cable anymore, I tend to forget how to fix the issue when it arises.  2018 has been a funny year for Microsoft patching.  Seems to be a crap shoot of what will break once you apply new patches.  Windows 10 patches haven't been immune to this. Here's how I fixed it. Download the PL2303_64bit_Installer.exe Unplug the USB-to-Serial Adapter Open up the previously downloaded exe. When prompted, plug in the…
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Troubleshooting Network Performance Issues

Cisco, Microsoft, Uncategorized, Windows
This won't be a tutorial, however, the purpose of this post is to highlight some common TCP/IP issues that degrade network performance. Network Congestion - If your firewall/router graphs your network usage, use that or obtain your current throughput (up/down) to your ISP. Use the current usage and then run a few speed tests in order to determine if your hardware is capable of hitting your maximum download/upload speeds you currently pay for. So if you have a 100 meg fiber circuit and your firewall is showing you are currently using about 60 megs at any given time, you should be able to get somewhere close to 40 megs on a download test from speedtest.net. If not, either your provider is not giving you the bandwidth you are paying for…
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Cisco – tcp-small-servers and udp-small-servers

blog, Cisco
For some truly unknown reason, Cisco's devices still have support for "small servers" or "simple services". Examples of these include echo, chargen, daytime and discard.  An attacker could possibly start a denial of service attack (DoS) against one or more network devices with those configured.  In this case; echo and chargen are to blame by allowing an attacker to cause  the chargen service to hit the echo services causing an endless loop of character generation and echo between the two hosts.  To disable this, simply enter the following commands: configure terminal no service tcp-small-servers no service udp-small-servers These commands can be run on nearly all IOS based Cisco equipment.
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Cisco Switching – switchport nonegotiate

blog, Cisco
Dynamic Trunking Protocol (DTP) is a standard feature of Cisco switches and allows two switches to dynamically configure interfaces interconnecting each other to be trunked ports.  DTP has 5 modes; Auto (default), On, Off, desirable and nonegotiate.  These 5 modes all have a purpose.  I have layed out the groundwork below: auto - The default setting allows the port to willingly convert to trunking, however, the port will not trunk unless the neighbor is set to on or desirable.  When two switches are connected together and set for auto, they will NOT trunk. on - This setting forces the port to be a trunk regardless of the neighbor's settings. off - This setting forces the port to not trunk, even if the neighbor is set to on. desirable - This…
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Cisco Command Reference

blog, Cisco
I was working on a client's network tonight and thought of about 10k topics to blog about.  All the commands on Cisco routers and switches.  The purpose of this would be to help remind me that the basics are not good enought and also expand your mind on what a command does, how to use it and possibly when to implement it.  If at any point I'm completely off my rocker, you know what to do :)
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