Skip to content

windows

How To Change The TCP/IP MTU On Windows Server 2016

Over the year’s I’ve had numerous occasions arise when I needed to change the MTU on a Windows based computer.  There are a million reasons why this is needed, such as the following.

  • Windows Servers deployed in an OpenStack environment require the MTU to be decreased to 1454 in order to work correctly with Neutron.
  • DSL very commonly uses a smaller 1492 byte MTU when deployed with PPPoE encapsulation, so performance can be significantly degraded if the router and computers are not decreased to match.
  • VPN connections over DSL and some WIFI networks are notorious for failing unless the MTU is adjusted.

 

What Affect Does MTU Have?

 

Packet size, also known as MTU or Maximum Transmission Unit, is the largest amount of data that can be transferred in one packet at the physical layer (OSI Layer 1) of the network. Ethernet’s default MTU is 1500 bytes without using Jumbo Frames.  For PPPoE the MTU is 1492 and dial-up connections typically used 576 back in the day.

Each transmission unit contains of header and actual data. This data is called the MSS, or Maximum Segment Size.  MSS defines the largest segment of TCP data that can be transmitted in a packet.  In a more summarized manner,

MTU=MSS + TCP & IP headers.

Click Here To Keep Reading!

Hacking In Windows Using Nishang With Windows PowerShell, Like A Boss!

As requested, this is the first post of many I’m doing on “hacking” and “pentesting.”  Many admins aren’t comfortable with Linux, or just want to use convenient Windows-based tools, so that’s what we’re going to do.  We’ll talk about a tool called Nishang, which you can use to do many different pentesting and security auditing techniques, using the Windows PowerShell 3.0.

To get started, you will need to download Nishang.  You can click here to go directly to the GibHub page or click the link below to download the latest version directly.  First, here’s a video the creator of Nishang gave at Defcon 21.

 

Download & Install

 

Click here to download the latest version of Nishang from GibHub (master.zip).

 

Once you’ve downloaded the zip file, extract it, rename the folder to nishang.ps and put it in the root of your c: drive.

 

snag-11-4-2016-3-52-07-pm

 

Open the Windows PowerShell command prompt as Administrator.  On Windows 10, click the start button and type “powershell” then right click and select “Run as Administrator.”

Click Here To Continue Reading!

Do You Have a Reliable IP Scanner Installed? Advanced IP Scanner is Quick & Easy.

Every Network Administrator or Security Administrator should have a few basic tools installed and ready to go at a moments notice.  Advanced IP scanner is a reliable and free network scanner.  It offers complete analysis of your entire LAN, showing live IP addresses and giving you the ability to remotely control systems with RDP and Radmin.  It’s installable or fully portable, so you can keep it in your Dropbox or NextCloud folder for convenient access.

 

Key features of Advanced IP Scanner include:

  • Remote Shutdown (and Wake-on-Lan)
  • MAC address to IP resolution
  • Exportable scan results via CSV
  • Quick access to discovered network shares
  • Remote Control via Radmin & RDP
  • Built-in tools such as SSH, tracert, telnet and ping.

 

Click Here to Keep Reading!

An Open Source, Command-Line App to Download Videos From Youtube & Over 100 Other Sites!

There is a wealth of outstanding content on Youtube and all of the other video sites online. Sometimes I like to download movies for trips, or training videos when I want to cut out distractions.

 

I found the solution; on Github of all places!  Youtube-dl is a simple command line executable you can use to download video quickly, with ease.  It supports hundreds of websites with video content.  Here’s how to use it on Windows.

 

How To Download Videos

 

First, we need to download the latest version of youtube-dl from Github. This link will always produce the latest version of youtube-dl, directly from Github:

 

https://yt-dl.org/downloads/latest/youtube-dl.exe

 

I suggest saving it in your “Videos” folder, located within your user folder.  You can find your user folder on your desktop. It’s the folder with your name.  There is a “Videos” folder already located there, by default.

Click Here To Keep Reading!

How to run Android apps (apk) using Google Chrome on Windows, OSX, and Linux

Last night I was in a pinch and needed to poke around in an Android app, but I didn’t have an Android phone or tablet with me. So, I started trying to figure out a way to run Android apps, or .APK files, on my Macbook Pro. The solution I found actually works on any desktop or laptop computer running Windows, OSX, or Linux. All you need is Google Chrome. It’s very easy and only takes about 30 seconds to setup. Here’s how to do it.

How to run Android Apps, .APK files, on your PC or MAC

You will only need a few items to do this.

The magic that runs Android apps in Chrome is ARC Welder. This app is developed by Google, and it’s pretty new. There are some compatibility issues with it and apps that require the Google Play store, but they are working through those issues relatively quickly. Let’s go ahead and download the Google ARC Welder app from the Chrome store.

Head over to this link and click “ADD TO CHROME” in the top right-hand corner of the box that pops up.

Click Here To Keep Reading This Post!

How To Add Windows Install Images To WDS (Windows Deployment Services) On Server 2012 R2

If you read my post on “How To Install WDS (Windows Deployment Services) on Windows Server 2012 R2.” you might be at a point where you have a WDS server set up, but you don’t have any Windows images loaded to install anything. Or, you might be having issues adding images to your WDS server. Either way, I’m here to help.

How to add images to WDS

Open up Windows Deployment Services by selecting it from the Tools menu on Server Management.

Screen Shot 2015-05-25 at 8.30.25 PM

If you have an ISO for Windows 7, Windows 8, Server 2008, or Server 2012, you’ll want to extract it using a tool like WinRAR, and move it over to your WDS server or make sure it’s available via a network share. If you are using a physical server and you have a CD ROM, you can put the OS installation CD in the drive as an alternative if you like. I prefer working with images.

There are two files we will need to add your first image. These are.

  • boot.wim – this is the Windows boot image
  • install.wim – this is the actual installation image

Click Here To Read The Entire Post!!

How To Install WDS (Windows Deployment Services) on Windows Server 2012 R2

This is the first in a three part series on “The Ultimate PXE Server Configuration.” PXE is the protocol that your network card can use to boot from the network. Having a good PXE server is a major need on every decently sized network or home lab. It’s really nice to never have to scrounge for a USB thumb drive or accumulate piles of burnt CDs that are only used once. All of those headaches can be avoided with a properly configured PXE server.

Microsoft Windows Server 2008 and 2012 both include what’s called WDS. This stands for Windows Deployment Services. This is a network boot (PXE) environment that allows you to install all sorts of different Windows versions, all over the network. A network install of Windows 7 or 8 over a gigabit network takes just a few minutes. It’s insanely fast.

In the Linux world, the defacto standard for PXE is the SysLinux package. It’s excellent for installing various Linux distributions, hypervisors (like vmware and xen), and tools (such as gparted, AV software, and disc cloning utilities). It even supports Windows installations, sort of. But, it’s quite a hassle.

In a perfect world, we would just combine both of these so that we can use WDS to take care of the Windows installations, and use SysLinux to handle linux installations, tools, and everything else. Well, guess what? You can, and that’s exactly what were going to to do in this series. The first post, the one you’re reading, covers installing WDS on Microsoft Windows Server 2012 R2. The second post will cover adding SysLinux to WDS. The third and final part will cover adding a ton of useful tools and installation sources. So, let’s get it started.

Installing WDS on Server 2012 R2

There are a few requirements for a WDS installation.

  • Active Directory – You need to run dcpromo on your WDS server to make it a domain controller if you don’t already have one already.
  • DHCP – It’s best to use Microsoft’s DHCP server, and like AD, I will be installing this service right along side WDS on a single server.
  • DNS – WDS needs DNS, which you will obviously have if you have a domain controller.
  • (Optional) Web Server – IIS will work well. Some packages install via http. This isn’t needed for Windows installation.
  • (Optional) NFS Server – The NFS Server role under file and storage services works well. This isn’t needed for Windows installation.

Click Here To Read The Rest Of The Post!