Saturday, January 24, 2015

DNS Information Groper for Windows

You can install the Bind DNS Information Groper (DIG) on your Windows machine. Dig is built into Mac and Linux and has a lot more features than the Windows nslookup tool.

Paul Heinlein has created a great page on using DIG at DIG How to. Paul’s page is well worth the time to read if you query DNS records on a regular basis. Dig -h will list all the available options.

To get DIG download BIND 9.10.1-P1. Follow the instructions in DIG DNS Tool for Windows 7 to install it.

Some useful links
Using the Dig Dns Tool on Windows 7

DIG How to

10 Linux DIG Command Examples for DNS Lookup

How can I see Time-to-live (TTL) for a DNS record?

Google’s page on DNS

Monday, January 12, 2015

IOS App to Scan WiFi Networks

IOS doesn't allow developers to directly access hardware so there aren't many low level network applications for IOS. But it turns out that even if you don't own an Apple Airport WiFi router you can use the Apple Airport utility to scan for wireless networks.

You will see the AP's MAC, the RSSI and the channel it is using. It's not as good as inSSIDer or WiFi analyzer on Android but it's free and a lot better than nothing.

Open the App Store on you iPhone or iPad and search for "Airport Utility". Tap "Get" and then "Install". When the app finishes installing Tap Open.

Once the app opens Tap "Wi-Fi Scan" at the top right. When the scanner opens Tap "Scan" on the top right. After a few seconds it will start displaying networks that it has found.

Sunday, January 11, 2015

PathTest for Kali Linux

You can read about how to use PathTest in the "PathTest on Windows" blog post. Here I explain how to get it working on Kali.

Download Pathtest to the tmp folder.

root@kali-32:/tmp# unzip
   creating: Linux_32-bit/
  inflating: Linux_32-bit/pathtest
root@kali-32:/tmp# ls

Run PathTest
root@kali-32:~/Linux_32-bit# ./pathtest -c

If you get an error:
"./pathtest: error while loading shared libraries: cannot open shared object file: No such file or directory" 

it's because Kali's crypto lib is named but Pathtest is expecting so we need to create a link between them.

First run "locate" to find libcrypto:
root@kali-32:/tmp/Linux_32-bit# locate libcrypto

Now we can create the Link:

root@kali-32:/tmp/Linux_32-bit# cd /usr/lib/i386-linux-gnu/
root@kali-32:/usr/lib/i386-linux-gnu# ln -s
root@kali-32:/usr/lib/i386-linux-gnu# ln -s
root@kali-32:/usr/lib/i386-linux-gnu# cd /
root@kali-32:/# cd /tmp
root@kali-32:/tmp# cd Linux_32-bit/
root@kali-32:/tmp/Linux_32-bit# ./pathtest -s
PathTest (TM) v.4.6.0 build 4639
Copyright (c) 2011, AppNeta Inc. All Rights Reserved.


PathTest for Windows

PathTest for Windows is a great tool! Since the DoE took over iPerf development there is no longer a Windows version. You can still run it using VMware Player but that isn't always easy or practical.

One good example is a Windows tablet. I recently had some wireless performance issues with a Dell Latitude 10 tablet running Windows 8 Pro. I put PathTest on a USB Flash drive and copied it to the table. There is no installation required, just copy the executable to the Tablet and test the wireless performance!

Screen shot of the test as seen on the Dell Latitude 10 tablet:
I keep iPerf3 on a Kali Linux virtual machine running on an ESXi server and PathTest on a Windows 7 virtual machine running on HyperV in the data center. This allows me to test from Windows, Mac, IOS and Linux machines on the fly with no additional setup.

And Hurricane Electric has a basic iPerf3 client for Android. I will blog about it in the near future.

With PathTest you can use the Windows or Linux versions together with either one being the server or client. You can also use either one as the server for the IOS app so there really is no excuse for not verifying your link speed when deploying a new infrastructure to use as a baseline or as the first step in trouble shooting performance issues.

Installing PathTest for Windows
The installation is simple but you have to register with Appneta, although it’s not too painful. To get started click the link below:

Download PathTest for Windows Here

Once the zip file is downloaded simply extract it to a folder of your choice.
Open a command window in the folder. Tip - on Win7 you can hold down shift while right clicking to get a menu with "Open Command Prompt Here" on it.

PathTest Server
To use this machine as the server simply type pathtest -s and press Enter.
This will start the server and you will see "Running in server mode on port 3236 ..." displayed.

PathTest Client
Repeat the steps above to download and unzip PathTest on the client.
To start a test enter
pathtest -c <Server IP> , Enter

This is the simplest command line and will run PathTest with all defaults. The defaults are:
Unidirectional - test client to server
DSCP - Not Set
Periodic Display of capacity Reports - Not Set
Protocol - UDP
Time - 5 Seconds

A more useful command would be:
pathtest -c --unidi -t 10

This will run a test in each direction for 5 seconds and print the results:

The above test was run on an HP laptop running Windows 7 connected over wifi to a Kali Linux virtual machine running on ESXi connected by Ethernet. I then moved the HP to a Gigabit switch and re-ran the test over Ethernet. Note that this test is 955Mbps.

PathTest for IOS

Why use PathTest
PathTest is available for both iPhone and iPad. It's a universal app so there is a different app for each device. They both work the same but the iPad app is a little more appealing due to the larger screen.

I keep PathTest running on a server in the data center. Whenever a user has an application problem they can quickly verify if the wireless is working correctly using PathTest. It's much better than sending a user to with all of the ads they have now.

You can also run a baseline when the network is deployed and then occasionally check performance. I ran it in an empty classroom and then with 36 students with iPads in the classroom. It was interesting to see the impact of 36 devices sending beacons.

It's a good tool for verifying changes to your wireless network since you don't have to go out to the public Internet to verify the throughput. Appneta does provide several public servers for your use so you can test your ISP's performance.

Installing PathTest for IOS
On your IOS device, open the App Store and search for pathtest. You will see the icon on the right. Tap Get, when the icon changes Tap INSTALL

To run a test on IOS:
Click the + sign in the upper left corner
Tap either Data Test or Voice Test
Next to Target tap “touch to change”
You can select one of Appneta’s servers or tap the + sign and add one of your devices.

Select the type of test - UDP, TCP, ICMP
Depending on the type of test you select you will be able to set various options

When the test finishes you can email the results. It sends a PDF with complete data from the test

Thursday, January 1, 2015

PathTest by Appneta


Appneta has free path testing application. It’s called Path Test and is available for IOS, Windows and Linux. You have to register with Appneta but it’s not too painful.
For IOS search the App Store for PathTest. For Windows and Linux use the links below:
Path Test Windows
Path Test Linux 32 bit
Path Test Linux 64 bit

PathTest on Windows and Linux is similar to iPerf3, if you have used iPerf3 it won't take long to get up to speed.  A big plus is that Appneta provides several public servers to test against.

PathTest on IOS is a graphical tool so it is different that the Windows/Linux versions. If you are an IOS users it's fairly easy to learn. See my blog on the IOS version for details.

I have a separate blog on how to use PathTest on each OS. You can use the navigation bar on the right to view those. Appneta has a PathTest Tips and Tricks site that is very informative - PathTest Tips and Tricks

Appneta is a fairly unique company that offers cloud based network and application performance monitoring.

They provide small appliances that you connect to your network to provide end to end performance monitoring. The data is analyzed and presented in Appneta’s cloud.

With their basic package you get an amazing amount of data about your WAN links. I have found missing links in a bundled T1 connection, missing DSCP markings and other carrier issues that are very difficult to trouble shoot.

They also offer several add on packages for monitoring and trouble shooting application performance. If you are running virtual desktops or Citrix sessions across a WAN you should do a trial.

They also have a nice Resources page you should review.