Saturday, 24 November 2012

Useful Win 7 Command for Wireless

This probably falls into that category: "stuff that everyone else already knows, but I don't", but I thought it was worth jotting down a few notes about.

I recently saw someone tweet about the command: "netsh show wlan <various options>", which I had never heard of before.

After having had a look through the command help screens, it seems an incredibly useful command if you want to quickly find out about the wireless networks and the wireless capabilities of a Windows 7 machine you're working on. Much of the information can be found by poking around in various GUI pages, but this command line utility is much quicker to use and gives a greater depth of information.

I'll just run through a few useful examples and then leave you to poke about in the help pages yourself if you want to know more.

A great way to get a summary of the wireless networks that a Win 7 client can hear is to open a command window (...or a DOS box as I like to call it) and enter the command: "netsh show wlan networks":

On the face of it, this maybe isn't massively impressive, but if you add the command switch "mode=BSSID", things get a little more interesting:

You now get to see some great information which includes authentication and encryption types, radio type (802.11g/n/a etc.) and channel. Very useful information.

 The final command variation I'll look at is: "netsh wlan show drivers". This command shows you extensive information about the radio types and authentication and encryption types supported by your wireless driver. I'm guessing that I need to caveat this by saying that there may be some hardware and even OS dependencies that need to be fulfilled for the client to actually support all of these:

Finally, there are plenty more options to play with, so have a poke about in the help screens and see if there are more useful nuggets you can find :) Here is the help screen output to whet your appetite:

(Update: I have been advised by a couple of very reliable people that this command also works on Windows 8)

Friday, 23 November 2012

Your system does not support long mode

Just a quick note for anyone who may come across a similar issue when trying to deploy server images on to their VMWare environment.

I've been lucky enough to get a new server recently to test various virtual WLCs and management packages that are being put out by various wireless vendors. But after installing ESXi and deploying a couple of server images, when I tried to start the virtual servers up, I kept getting the following messages popping up in vShere:

(For search engine benefit: This virtual machine is configured for 64-bit operating systems. However, 64-bit operation is not possible. Longmode is not possible. Longmode is disabled for this virtual machine)

Also, in the console of the server (Cisco MSE & NCS), I was getting the following reported: "Your CPU does not support long mode. use a 32 bit distribution"

I was concerned that maybe there was an issue with my server CPU, in terms of support for virtualization. 

I rebooted the server and dropped in to the BIOS setup and found that the virtualization parameter for the processor settings was set to disabled! So, I enabled it and rebooted. But, the issue persisted :(

So, I dropped in to the BIOS setup again and noticed a little note that said that a complete power-off was required once the virtualization setting had been changed.

A few minutes later, after a complete power off, my virtual servers were finally booting correctly!

Probably a complete noobie error, but we've all got to start somewhere :)

Wednesday, 21 November 2012

Cisco DTLS License

The whole area around the free DTLS license that can be obtained for Cisco WLCs has always been a bit of a head-scratcher for me.

I'm never sure whether I need the additional license or I already have it to be honest. Anyhow, today on my home lab I tried to have a look at some features which required DTLS between the AP & WLC, only to find that my 2504 did not support the option (the option was grayed out).

After some digging around on the Cisco forums, I found that the following licensing link can be used to obtain the DTLS entitlement license with very little fuss at all:

The information to be entered can be found on the WLC inventory page. Only the model number & serial number are required.

Within seconds, I had the license (which can be downloaded directly or sent by email) and applied it to my 2504 (Management > Software Activation > Commands > Install License)