Installing Plixer’s “Scrutinizer” NPMD

Plixer makes a good “Network Performance Monitoring and Diagnostics” (NPMD) application called “Scrutinizer“. NPMD, as Gartner calls it, mostly omeans, collecting, aggregating, and reporting on Netflow data.

Plixer provides a VMware OVF for installation of a virtual appliance. I, however, ran into a few issues with the installation:

I couldn’t get the install to work . . . → Read More: Installing Plixer’s “Scrutinizer” NPMD

Fix Apple Bonjour with Cisco autonomous APs

I purchased some used Cisco C1140 autonomous access points for my home network (autonomous meaning not lightweight or requiring a WLC). While everything seemed to be fine at first, later we noticed that printouts to our Canon laser printer were no longer working from our Macs. After some research I realized that the Macs were . . . → Read More: Fix Apple Bonjour with Cisco autonomous APs

How to probe ethernet capabilities…

Mostly for my own edification – use “ethtool”, eg:

You’ll note two important details about this output:

This NIC is gig capable but is only running at 100mbs. I claim to be running this as root, but any good sysad should be using “sudo” instead!

Anyway, simple command, but sometimes you forget them.

. . . → Read More: How to probe ethernet capabilities…

Why is WLAN “signal quality” in negative decibels?

If you use “iwconfig” on Linux to get statistics on your wireless LAN you’ll note that the “Signal Level” is expressed in negative decibels. On the surface that would appear confusing – how can decibels be negative?!

Fortunately an anonymous poster explains at Toms Hardware:

Absolute power of a signal is measured in wattage. The . . . → Read More: Why is WLAN “signal quality” in negative decibels?

Larry Ellison on “Cloud Computing”

Via SwissInfo:

“The computer industry is the only industry that is more fashion-driven than women’s fashion,” Oracle founder Larry Ellison commented on cloud computing recently. “Maybe I’m an idiot, but I have no idea what anyone is talking about. What is it? It’s complete gibberish. It’s insane.”

I think there’s more to it than just . . . → Read More: Larry Ellison on “Cloud Computing”

Defaulting a Cisco interface…

One pain with Cisco IOS is trying to get a configured interface back to defaults. Half the time you don’t even remember what those were.

If it’s a sub-interface you can “no” it, but you will still have configuration left behind:

cisco(config)#no interface ATM1/0.1 Not all config may be removed and may reappear after reactivating . . . → Read More: Defaulting a Cisco interface…

How to remove a VLAN from a port in CatOS…

I can never seem to remember how to “remove” a VLAN on a switch (eg: Cisco 6500) running the older CatOS. The new IOS based switches are much easier.

Anyway, it’s actually quite simple, just force the port to VLAN 1 (assuming that is your default/native VLAN). For example if port 6/5 was set to . . . → Read More: How to remove a VLAN from a port in CatOS…

Where to find the Windows XP “hosts” file

Just like Unix you can add a static host to the Windows system. On Windows XP the file is usually found in the “intuitive” location here (may change depending on where you loaded Windows):


This is also where the “lmhosts” file is found.

The format is in standard ARPANET format. For more . . . → Read More: Where to find the Windows XP “hosts” file

WPA versus WPA2?

So what’s the difference?

Not much or a lot depending on your opinion. WPA uses TKIP for key management, whereas WPA2 uses AES-CCMP. Usually depending on how the AP has been set up, you can use either (TKIP or AES-CCMP) interchangeably, thus using WPA or WPA2 as needed. Many older devices like those running Windows . . . → Read More: WPA versus WPA2?

WPA resources

When researching using WPA on Ciscos I ran into a lot of useful URLs as resources. If you’re in the same bind, you may find them helpful too:

Not a pretty list, but still good to . . . → Read More: WPA resources