Jay R. Wren - lazy dawg evarlast » Networking

My Whole App is a LINQ Expression

jrwren — Sun, 10 Jan 2010 20:53:03 +0000

I just published an application which I consider useful over on codeplex with source hosted on launchpad.

http://wlanchannelinfo.codeplex.com/

https://code.edge.launchpad.net/~evarlast/+junk/WlanChannelInfo

I wrote this because Wifi in my home is very slow. Its so slow I’m tempted to run a network cable to my couch so that even when I’m couch surfing I can have fast access to my server.

In an effort to diagnose my slow Wifi, I tried to see if my neighbors were causing interference by running Wifi on the same or overlapping channel as me. I downloaded netstumbler; it didn’t work. I downloaded some other tool; neither did it.

So I wondered how hard it would be to write my own. It turns out Windows 7 added to the Wlan* api to expose all of the necessary data. After some digging I found the managedwlan project on codeplex. Now I got to play.

Once I figured out the api, I was able to write the entire application with pretty much one LINQ expression:

var client = new WlanClient();
var retval =
from wlanIface in client.Interfaces
from bssentry in wlanIface.GetNetworkBssList()
from network in wlanIface.GetAvailableNetworkList(Wlan.WlanGetAvailableNetworkFlags.IncludeAllAdhocProfiles)
where InterfaceService.GetStringForSSID(network.dot11Ssid) == InterfaceService.GetStringForSSID(bssentry.dot11Ssid)
select new WifiInfo
{
bssentry = GetStringForSSID(bssentry.dot11Ssid),
channel = Wifi.FrequencyChannelMap[bssentry.chCenterFrequency],
frequency = bssentry.chCenterFrequency,
linqQuality = bssentry.linkQuality,
strength = bssentry.rssi,
signalQuality = network.wlanSignalQuality,
wifitype = network.dot11BssType
};

The result of that expression is directly databound to a WPF DataGrid and I can now view the data that I want to.

I really love the platform (C#+.NET) on which I work.

Restoring a Desktop Image to a VMware Virtual Machine with Windows Home Server

jrwren — Sat, 10 Oct 2009 00:58:55 +0000

Copy the restorecd.iso from \\homeserver\Software\Home PC Restore CD to your VMware server.
Configure a new VMware virtual machine with an appropriately sized disk, a network adapter (I prefer bridged) and a CD ROM Drive pointed to said restorecd.iso from step 1. Do not start the VM at the last step.
Find the vmx file created in step 2. Add a line ethernet0.virtualDev= “e1000”. This the required trick step since Windows Home Server doesn’t have a driver for the LANCE network chip which vmware normally emulates.
Boot the Virtual Machine and follow the prompts.

nmap can open device eth15, but only if you let it

jrwren — Wed, 10 Jun 2009 00:44:00 +0000

This is here as a note to myself to not be stupid.

I’ve remembered at forgotten this at least 4 times and so that makes me stupid for not remembering.

When nmap on win32 tells you that “dnet: Failed to open device eth15”, it is really suggesting that you run it as administrator.

You need to be administrator to access the network device at this level.