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WarWalking (1)


What exactly is a \’WarDriver\’? WarDriver: One who locates and logs
wireless access points while in motion ;[benign]. WarDriving was
invented by Peter Shipley and now commonly practiced by hobbyists,
hackers and security analysts worldwide. More information about this
trend can be found at wardriving.com. Even if you are not into this
sport, the following (innocent) software may be of use to obtain
information about your wireless network. In a next message I\’ll discuss
a few less innocent software tools. Probably the most popular network
scanner
for Mac OSX is MacStumbler. It detects nearby wireless networks,
tells you the channels they use, whether they use WEP
(encryption), give their signal (and noise) strength, the name of the
network and if you click on the Details button it gives you
(among other things) the MAC-address. A similar tool is iStumbler. It
gives roughly the same information : SSID (name). MAC-address,
signal/noise, channel and whether it is encrypted. More information is
available from the iStumbler manual. In addition it presents a
signal graph which is useful if you are trying to decide on which
signal you will let your Airport-basestation broadcast. Using
iStumbler i discovered that there was a recurrent noise at
channel 5 every couple of minutes (don\’t ask what it was) but that on
channel 1 the signal was not interrupted.

Both
MacStumbler and iStumbler are active scanners
meaning that they send out probe request to nearby access points. As a
result they are not able to detect closed networks. To detect
them you need far more intrusive passive scanning software, but
that is for next time.

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dinner’s ready

Not
all improvements to our home-network need to be high tech. Here is a
very simple measure which reduces the amount of in-house shouting
drastically. Often all of us are online, either to work, surf the net,
MSN-chat or listening to iTunes and clearly we can easily see which
other computers are on at the time. Just click on the Network
icon on the top left of the Finder-window. As our computer-names
are quite descriptive (iMacLieven,iMacBente,eMacAnn,iBookGitte)
it will give a good indication of who is online but as we can all login
to all these computers one can never be too certain. An elegant way to
find out who is on whose computer is to use the Rendezvous window
in iChat. This lists all people on the network which have
iChat running
on their computers and then iChat can be used to send
simple messages immediately to a given person (such as : turn that music
down or telephone for you etc.). There is just one problem : as the kids
use MSN to chat they never turn on iChat and as we are of a non-chatting
generation neither do we. Fortunately, it is easy to force iChat to be
running at login.

On each computer go to
SystemPrefrences-Accounts and for each user go to the Startup
Items
pane. Click on the + button and browse to the
Applications/iChat program and click Add. Be sure to check
the Hide button and you are done. Next time that person logs in,
iChat will start automatically in the background (the only slightly
annoying thing is a small sound at the end of login) and the user will
appear in any iChat-Rendezvous window.

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graphite ABS can be used


I found on the net a way around the problem that a first
generation graphite airport basestation is not compatible with a
third generation extreme ABS. The article is called Extending AirPort’s range with multiple base
stations
and addresses precisely my problem (a problem that others
still think is not there judging from the replies to the article). I
checked it out and it works. So, here is the setup that I will use this
summer to get some iBooks in the garden connecting happily to the
internet at the expense of an in-house extra computer running… The
extreme ABS (woonkamer) is configured to run our usual in-house
network. The graphite ABS (terras) will be connected via a
crossed-ethernet cable to an iMac in the dinner room near the garden
window (this iMac is still well within the range of the
woonkamer-network). Here are the System-preferences for the iMac :


Network : Airport : TCP/IP configure using
DHCP ; all others empty
Network : Build-in Ethernet : TCP/IP
configure using DHCP ; all others empty
Sharing : Internet :
Click ‘Start’ for sharing your Airport connection

Here are the configuration parameters of the terras-ABS
:

Internet tab
Connect using:
Ethernet
Configure: Using DHCP
IP address: leave
empty
Subnet mask: leave empty
Router address: leave
empty
DNS servers: leave empty
Domain name: leave
empty
DHCP client ID: leave empty

Network tab
Distribute IP address: CHECKED
Share a single IP address (using DHCP and NAT): CHECKED
DHCP lease: 60 min (default)
Enable AirPort to Ethernet
bridging: CHECKED
all others: leave empty / unchecked

Now any iBook in the garden connecting via Airport to
the terras-network will be able to get on the net.

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internet’s backbones

Did you ever wonder what hardware keeps the web running ?
Fibre-optic cables, cross-continent cables and the like seem to be a
dull subject but in the hands of Neal Stephenson. When he was doing research for his excellent book Cryptonomicon he travelled the continents
following the biggest backbone cable to be laid and wrote down his
journey for Wired Magazine in Mother Earth, Mother board. Here are his opening
lines : “In which the hacker tourist ventures forth across the wide and
wondrous meatspace of three continents, acquainting himself with the
customs and dialects of the exotic Manhole Villagers of Thailand, the
U-Turn Tunnelers of the Nile Delta, the Cable Nomads of Lan tao Island,
the Slack Control Wizards of Chelmsford, the Subterranean
Ex-Telegraphers of Cornwall, and other previously unknown and
unchronicled folk; also, biographical sketches of the two long-dead
Supreme Ninja Hacker Mage Lords of global telecommunications, and other
material pertaining to the business and technology of Undersea
Fiber-Optic Cables, as well as an account of the laying of the longest
wire on Earth, which should not be without interest to the readers of
Wired.”

Probably this long text is a bit tiring to
read from screen so I made a pdf-file of it which should be easy to print out.
Enjoy the read!

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the best LaTeX system

If you are
a mathematician, you’d better have a functioning TeX on your computer
which I do not have at the moment as I completely erased my HD yesterday
and started brand new. Some time ago this would make me slightly nervous
but as I did install TeX on a number of computers recently I hope to get
it up and running in no time. However, as the install process changes
slighly each time I’ll log here my actions for future reference.
Further this log may convince you to buy a Macintosh because I really do
not know of a better TeX system around.

A good source
for TeX material is the PennState Mac-TeX page. The
first thing to do is to get a good editor such as the freeware BBedit
Lite
but the present link directs to the commercial version so has this
Lite version been taken off the net? Fortunately not, a quick
Google tells me that BareBones still maintain a BBedit Lite page from which you can get the 6.1.2
version (it contains a version for OS X and one running under System 9),
so copy the BBedit Folder to the ApplicationFolder and the OSX program
to the Dock.

Next, we will need a spelling checker
like Excalibur which you can find under the
Tools/Utilities of the PennState-site. So download from the links
: Excalibur 4.0 (782k), the Mathematical Lexicon (29k) and the Dutch
dictionary (791k), put these two Folders (or any other Dictionaries you
like to download) in the ExcaliburFolder and copy this to the
ApplicationsFolder and Excalibur itself to the Dock. These matters
settled, it is now time for the big gun : TeX itself.

You can get there from the Engines subsection of the
PennSate site but it’s better to go directly to the excellent TeX on Mac OS X page and follow the instructions (which as I mentioned before tend
to change slightly). I used to get the iInstaller first and
install then the required packages but this time I’ll go for the quick
and dirty route : I’ll get myself the TeX-fat.dmg disk image
(77Mb) which contains TeX and Ghostscript 8 and the i-Installer!
What you obtain is a Volume with the i-Installer, a i-Packages
Folder, some files to read and the TeX-fat.iid. Take the
i-Installer to the Applications/Utilities Folder and to the Dock.
Drag the TeX-fat.iid file on the mounted volume on the i-Installer
application icon. You will be presented with an i-Directory with two
packages on the volume. Install all of them. It is best to install
ghostscript after you have installed TeX as it may contain configuration
material that can take advantage of TeX. I got a warning message but
choose to ignore it, seems to install as expected. Along the way you are
asked a few simple questions (such as paper size, formats you want to
have etc.) when in doubt go for the default! Okay : Task finished! But I
still have to install the ghostscript 8 package but this goes a lot
faster. So we should now have a working TeX installation but are still
missing a front-end. These you can download fllowing the links at
the beginning of the TeX on Mac OS X page. I usually go for TeXShop which is a 3.1Mb disk-image download. Drag
TeXShop into the ApplicationsFolder and the Dock. Find the file named
“pdfsync.sty” in the distribution directory. Drag a copy of this file
to ~/Library/texmf/tex/latex. Here ~/Library is the Library folder in
your home directory. You may need to create the folders texmf, tex, and
latex if they do not already exist. Alternatively, you can gp for iTeXMac (I never figured out what went wrong
between these two developers, but surely it was something
big).

At a later stage I am sure I want to add
new style files from CTAN. So here is the drill : copy them in the
diectory

/usr/local/teTeX/share/texmf.local/tex/latex/…

and do a texhash from the command line (as root).
I noticed that lately one do no longer need to adjust parameters to get
a heavy xy-pic file being compiled but if one does not to change any of
the values : be root and go to

/usr/local/teTeX/share/texmf/web2c/texmf.cnf

increase values and do a texhash. Finally, if you want to
print chess or go-diagrams or other fancy pictures requiring
metafont files here is the drill : be root and copy the .mf files
in an apropriate directory under

/usr/local/teTeX/share/texmf/fonts/source/public/

(if necessary change the owner of the directory) and
then do a texhash.

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