Archive for the ‘Sharing’ Category

MAC or Media Access Control is the other name for Ethernet Card Address. Ethernet was originally developed by Xerox then further developed by Xerox-DEC-Intel. Before the name was Alohanet. The name was taken from Palo Alto Research Center Aloha Network.

Ethernet was named by Robert Metcalfe. Maybe, Ethernet means carry data everywhere throughout the network.

MAC address is the true name for a computer in a LAN. It’s usually expressed with 12 digits hexadecimal number. (Example: 00:0d:88:b3:72:f3)

When you are connected to a LAN, your IP number will be translated to MAC address by a protocol called ARP (Address Resolution Protocol).

Let’s say, you use computer A with IP

Computer B has an IP

When you send a package to computer B, there are few steps run behind the scene. But these steps are based on LAN configurations. I’m sure that almost all LAN use star topology now.

The first generation of star topology use HUB to connect the all computers. Now, we use SWITCH.

Using HUB
When computer A ( sends a package to computer B (, first it will send a broadcast message to all computers in that LAN. Same like, when send a package to Alan, in front of the door, you scream, ‘Hey, who is ALAN?’. If Alan is there, he will say, ‘I’m Alan’ then you deliver the package to him.

When computer A ( sends a package to computer B (, it will send directly to computer B. Because Switch has everybody’s MAC address in its memory. So, you don’t have to scream.

What is the purpose MAC address for Administrator?

If you read my article about DHCP server,



lease {

starts 5 2007/10/05 22:37:02;

ends 5 2007/10/05 23:37:02;

tstp 5 2007/10/05 23:37:02;

binding state free;

hardware ethernet 00:0d:88:b3:72:f3;



You see that IP is only used for MAC 00:0d:88:b3:72:f3. Mean, it won’t work if somebody try to use this IP address with another PC. Off course it’s very easy to hack because in Linux you can change your MAC address easily. If you know, :).

taufanlubis@toshiba:~$ ifconfig | grep Ethernet

eth0 Link encap:Ethernet HWaddr 00:A0:XX:XX:XX:XX

eth1 Link encap:Ethernet HWaddr 00:1B:XX:XX:XX:XX

eth0:avah Link encap:Ethernet HWaddr 00:A0:XX:XX:XX:XX


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A Domain Name Server (DNS) for NAT networking could not be determined. Please, check your /etc/resolv.conf for nameserver entries. Either add one manually (man resolv.conf) or ensure that your host is correctly connected to an ISP. If you ignore this warning the guest will not be able to perform nameserver lookups and it will probably observe delays if trying so.

This error occurs when your Virtual Box’s guest try access internet but the main Operating System’s DNS hasn’t been set yet. To fix it, just add your Internet Service Provider (ISP)’s IP to your DNS.

In Ubuntu, the DNS file is /etc/resolv.conf.

Open System > Administration > Network > DNS and add your ISP’s IP to ‘DNS server List Box‘ then refresh the connection.



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Sometimes, when you try to unmount a disk you get an error “Cannot umount volume. An application is preventing the volume ‘…….’ from being umounted.”

For this test, I open a mp3 file then I try to unmount the disk.

taufanlubis@toshiba:/media$ sudo umount Maxtor/

umount: /media/Maxtor: device is busy
umount: /media/Maxtor: device is busy


To determine the cause of the busy device you can use ‘lsof (list of open files)’. An open file may be a regular file, a directory, a block special file, a character special file, an executing text reference, a library, a stream or a network file.

You have to use ‘lsof‘ as a superuser.

taufanlubis@toshiba:~$ sudo lsof /media/Maxtor

xmms 6731 taufanlubis 8r REG 8,17 3766597 77718 /media/Maxtor/Data Music/My Music-Pop/Alpha Ville- Big In Japan.mp3


Now, I know why I can’t unmount my disk because there is one file that still open.

You apply the same method when you find an error ‘Could not bind to port’. For example, you want to know what applications that currently use port 80.

taufanlubis@toshiba:~$ sudo lsof -i:80

[sudo] password for taufanlubis:
apache2 5649 root 3u IPv4 18026 TCP *:www (LISTEN)
apache2 5739 www-data 3u IPv4 18026 TCP *:www (LISTEN)
apache2 5741 www-data 3u IPv4 18026 TCP *:www (LISTEN)
apache2 5742 www-data 3u IPv4 18026 TCP *:www (LISTEN)
apache2 5743 www-data 3u IPv4 18026 TCP *:www (LISTEN)
apache2 5744 www-data 3u IPv4 18026 TCP *:www (LISTEN)


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The wireless keyboard and Mouse that I use are BenQ, ‘BenQ IM230 Wireless Media Desktop Companion’ package. It’s designed to work under Windows 2000, ME and XP. The price is at about Rp 290.000 (31 US$).


Package contents:

  • BenQ IM230 wireless keyboard

  • BenQ IM230 wireless optical mouse

  • Wireless receiver

  • AA Alkaline batteries (4 each)

  • User’s guide

Internet Hot Keys:

  • Email: launch default email program

  • My Home: launch default web browser

  • Search: launch the file search or web search window

  • Refresh: refresh current page

  • Next: Go to the next web page

  • Previous: Go to the previous web page

Media Console Hot keys:

  • Volume down

  • Mute

  • Volume Up

  • Previous track

  • Next track

  • Stop

  • Play/Pause

Establishing Wireless Connection with Ubuntu Gutsy

I just can’t believe, because when I tried at the store, the technician need to press the CONNECT button at the receiver, wait until the indicator light start to blink and then he reset both mouse and keyboard within 10 seconds before it can connect.

When I plug the Wireless Receiver’s USB cable into my USB port, Gutsy recognize it in 2 seconds then I can operate both the Keyboard and Mouse directly and smoothly. I still can operate it in 3 meter range.


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To reduce the loading process you can change the default setting of Open Office. To change the default setting, open any of your Open Office application. Go to Tools > Options > OpenOffice.org.

  • Number of steps : 10 (this is for your ‘undo‘ steps).

  • Use for OpenOffice.org : 128MB (increase it if you have more memories).

  • Enable systray Quickstarter : enabled



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I think PSP is one of great game devices have ever made. You can play games, hear music, see video, see photo, take photo (additional device) even browsing the internet with its wifi capabilities.

When you plug the PSP to your Ubuntu with USB cable, it will act like a flash disk. So, you can upload or download any data that you like.

How can I do it?

First, connect the PSP to your Ubuntu with USB cable.


From PSP, Go to ‘settings‘ and choose ‘USB Connection‘.

Wait, for few seconds then you will get a new disk icon on your desktop. The icon will be different based on your themes. I use Mac Leopard themes, so I got an icon like below.

Now, you can double-click the icon to go to PSP directory.

Don’t get confuse with so may directories displayed in your PSP. Then main directories are:

  • VIDEO – for mpeg-3 dan mpeg-4 format (don’t create sub-directory)

  • PSP –

    • COMMON

    • GAME

    • SAVEDATA – for your saved games.

    • SYSTEM

  • PICTURE – for photo (can create sub-directories)

  • MUSIC – for your music (don’t create sub-directory)

  • ISO – for your games (don’t create sub-directory)


You can save your ‘saved games’ . For example, when you play Tekken (my favorite) until few levels then you remove the game from the PSP, your ‘game levels’ is still kept in the ‘SAVEDATA’ directory. So, next time you install the Tekken again, you still can play with your old ‘game levels’. The concept is the same like PS1, PS2 or PS3. You can change any discs but your level is saved in your memory card.

I think it’s cool idea. So, you can install or remove any games…..

Sample of the ISO directory in my PSP.

Sample of the saved games in my PSP.

Sample of the music directory in my PSP.

Sample of the wallpapper directory in my PSP.

One thing I still can’t find until now is, set my Linux machine acts as server and my PSP as a client. Cool right?

I can do that in Windows. So, I don’t have to upload or remove big game files to my PSP. For your information, PSP games size are from 70MB to 1.5GB meanwhile my Sony Stick Duo memory card is only 2GB.

There are so many web sites provide games for PSP but I think www.pspiso.com is best. Usually games with big file size are divided into few links. If you want it easier, just choose a game with one link only (1 file = 1 game, not split), so you don’t have to merge it again.

My psp iso collections:

taufanlubis@toshiba:/media/Maxtor/Data Game/PSP/ISO Collections$ ls -lh

total 15G
-rwxrwxrwx 2 root root 127M 2006-10-14 16:11 Avatar – The Last Airbender.CSO
-rwxrwxrwx 2 root root 280M 2007-02-12 18:50 Blade Dancer – Lineage of Light.cso
-rwxrwxrwx 2 root root 112M 2007-02-22 22:53 Coded Arms.cso
drwxrwxrwx 1 root root 4.0K 2007-04-24 14:33 cover game
-rwxrwxrwx 1 root root 135M 2006-10-04 17:43 Daxter.cso
-rwxrwxrwx 2 root root 105M 2007-02-12 18:46 Dead to Rights – Reckoning.cso
-rwxrwxrwx 2 root root 185M 2005-07-02 08:20 DEATH 2 RIGHT.iso
-rwxrwxrwx 2 root root 163M 2006-06-16 12:21 Fight Night Round 3.cso
-rwxrwxrwx 2 root root 702M 2007-02-09 22:08 Ghost Rider.cso
-rwxrwxrwx 2 root root 870M 2006-10-31 15:30 Grand Theft Auto.cso
-rwxrwxrwx 2 root root 297M 2006-09-05 21:09 Harry Potter and The Goblet of Fire.cso
-rwxrwxrwx 1 root root 4.2K 2007-05-27 16:04 iso.txt
-rwxrwxrwx 1 root root 563M 2007-02-08 21:17 Locoroco.ISO
-rwxrwxrwx 1 root root 381M 2007-05-27 09:34 LocoRoco.rar
-rwxrwxrwx 2 root root 102M 2007-01-17 21:00 Marvel – Nemesis.cso
-rwxrwxrwx 2 root root 266M 2006-10-27 02:08 Marvel – Ultimate Alliance.cso
-rwxrwxrwx 2 root root 819M 2006-12-06 11:45 Metal Gear Solid – Portable Ops.cso
-rwxrwxrwx 2 root root 22M 2007-04-05 07:35 Mind_Quiz.cso
-rwxrwxrwx 2 root root 639M 2006-06-13 15:37 Monster_Hunter_Freedom.cso
-rwxrwxrwx 2 root root 1.1G 2006-11-17 07:06 Mortal Kombat – Unchained.cso
-rwxrwxrwx 2 root root 186M 2007-01-18 19:21 Online Chess Kingdom.cso
-rwxrwxrwx 2 root root 171M 2007-01-24 18:21 PacMan – World 3.cso
-rwxrwxrwx 2 root root 125M 2006-08-26 23:04 PacMan – World Rally.cso
-rwxrwxrwx 2 root root 326M 2006-10-18 14:02 Power Stone Collection.cso
-rwxrwxrwx 2 root root 711M 2007-02-05 20:21 Prince Of Persia – Revelations.cso
-rwxrwxrwx 2 root root 801M 2006-11-28 18:27 Pro Evolution Soccer 6.cso
-rwxrwxrwx 2 root root 17M 2005-06-08 05:20 Puzzle_Bobble_JAP_PSP-DEV.ISO
-rwxrwxrwx 2 root root 161M 2007-02-13 16:22 Ridge Racer 2 – Japan Version.cso
-rwxrwxrwx 2 root root 184M 2005-09-18 05:26 Ridgeracer.iso
-rwxrwxrwx 2 root root 291M 2006-03-14 20:01 Samurai Warrior.iso
-rwxrwxrwx 2 root root 16M 2007-03-11 11:28 Secret War (2004) #001.cbr
-rwxrwxrwx 2 root root 188M 2007-01-24 10:01 Sid Meirs Pirates – Live the Life.cso
-rwxrwxrwx 2 root root 92M 2006-11-10 17:17 Socom – Navy Seals-Fire Team Bravo 2.cso
-rwxrwxrwx 1 root root 102M 2006-11-18 13:49 Sonic.cso
-rwxrwxrwx 2 root root 75M 2005-07-28 20:15 Star Soldier.iso
-rwxrwxrwx 2 root root 97M 2006-08-05 12:50 Street Fighter – Alpha3 Max Pal.cso
-rwxrwxrwx 2 root root 231M 2006-06-29 12:49 Syphon Filter – Dark Mirror.cso
-rwxrwxrwx 1 root root 768M 2006-07-08 16:54 tekken.cso
-rwxrwxrwx 2 root root 1.2G 2006-07-26 16:35 Tekken – Dark Resurrection.cso
-rwxrwxrwx 2 root root 302M 2007-02-10 19:44 Tenchu – Time of Assasins.cso
-rwxrwxrwx 1 root root 462M 2006-06-07 14:46 TheSims2.cso
-rwxrwxrwx 2 root root 272M 2006-08-31 01:55 Ultimate Ghosts n Goblins.cso
-rwxrwxrwx 2 root root 176M 2007-02-12 19:36 Untold Legends – Brotherhood of the Blade.cso
-rwxrwxrwx 2 root root 602M 2007-02-12 19:40 Valkyrie Profile – Lenneth.cso
-rwxrwxrwx 2 root root 379M 2007-01-17 21:01 Winning Eleven 9 ENG.cso
-rwxrwxrwx 1 root root 155M 2007-01-17 20:58 WipeOut.cso
-rwxrwxrwx 2 root root 432M 2007-02-22 16:43 X-Men Legends 2. – Rise of the Apocalypse.cso

taufanlubis@toshiba:/media/Maxtor/Data Game/PSP/ISO Collections$

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When I turn my laptop this afternoon, I suddenly lost my sound and got this ugly red cross beside my speaker.

When I double click the icon, I got this message.

Then I open System > Preferences > Sound ……I lost my sound device.
I can’t run ‘alsamixer’ from the terminal, then I did log off and reboot the system …..
nothing to make the sound work.
The last thing I did was I regularly update my system using:
taufanlubis@toshiba:~$ sudo apt-get update
taufanlubis@toshiba:~$ sudo apt-get upgrade
taufanlubis@toshiba:~$ sudo apt-get dist-upgrade

It’s normal daily routine that I do every day and I always use the ‘main server’ for my repository, so I’m very sure that it didn’t cause the problem.

When I googled, I found a solution in here. This blog belongs to Kamil.

He mentioned that it could probably a a Gnome bug and is most likely distribution independent. I agree that it may caused by independent distribution. When you install something using Sypnatic Package Manager, any programs that have been tested by Ubuntu Team and compatible with it has a Ubuntu logo beside the package title.



Because, there’s so many applications that I’ve run in my laptop.

But, who cares….. If you wanna try a new thing then you have to be ready with consequences.


The point is how we can fix the problem. So, here it is.

Problem 1. I don’t have any more access to my audio.

taufanlubis@toshiba:~$ ls -l /dev/snd
total 0
crw——- 1 root audio 116, 3 2007-12-20 12:51 seq
crw——- 1 root audio 116, 2 2007-12-20 12:51 timer


If you see the list in my /dev/snd directory, the access is only for root. Then I gave a new access to me (taufanlubis).

taufanlubis@toshiba:~$ sudo chmod -R a+rwx /dev/snd

for temporary access. But, I got a new error message.


Then I try to make it permanent.

taufanlubis@toshiba:~$ sudo adduser taufanlubis audio

The user `taufanlubis’ is already a member of `audio’.


Strange, now I’m part of the groups but I still can’t hear the sound.

I though it’s caused by Gstreamer plugins.

So, I did update my system again ….

taufanlubis@toshiba:~$ sudo apt-get update

taufanlubis@toshiba:~$ sudo apt-get upgrade

taufanlubis@toshiba:~$ sudo apt-get dist-upgrade

…. and restart my laptop again.


Problem 2. I lost my sound device.

But, still there is no sound.

Then, I just realized that I don’t have my /dev/dsp, /dev/mixer, /dev/snd/pcm* anymore.

That’s why, I can’t run alsamixer from my terminal.


So, re-install my sound driver. Now, I got my device back.

taufanlubis@toshiba:~$ ls -l /dev/snd
total 0
crw——- 1 root audio 116, 0 2007-12-20 19:40 controlC0
crw——- 1 root audio 116, 4 2007-12-20 19:40 hwC0D0
crw——- 1 root audio 116, 5 2007-12-20 19:40 hwC0D1
crw——- 1 root audio 116, 24 2007-12-20 19:40 pcmC0D0c
crw——- 1 root audio 116, 16 2007-12-20 19:40 pcmC0D0p
crw——- 1 root audio 116, 30 2007-12-20 19:40 pcmC0D6c
crw——- 1 root audio 116, 22 2007-12-20 19:40 pcmC0D6p
crw——- 1 root audio 116, 1 2007-12-20 19:40 seq
crw——- 1 root audio 116, 33 2007-12-20 19:40 timer




taufanlubis@toshiba:~$ ls -l /dev/dsp
crw——- 1 root audio 14, 3 2007-12-20 19:40 /dev/dsp
taufanlubis@toshiba:~$ ls -l /dev/mixer
crw——- 1 root audio 14, 0 2007-12-20 19:40 /dev/mixer


Problem 3. I lost my access to System > Administration > Users and Groups.

I don’t know how but I don’t have any access to ‘Users and Groups’ which is bad because I can’t set the permission to my user login (taufanlubis).

The only way is I have to run it as ‘root‘. So, I opened my terminal, Application > Accessories > Terminal, login as root and open ‘users-admin’ application.

Then, I updated my ‘User Privileges’ and reboot the system.


I have my sound back.

Checked again the permission.

taufanlubis@toshiba:~$ ls -l /dev/snd
total 0
crw-rw—- 1 root audio 116, 0 2007-12-20 19:40 controlC0
crw-rw—- 1 root audio 116, 4 2007-12-20 19:40 hwC0D0
crw-rw—- 1 root audio 116, 5 2007-12-20 19:40 hwC0D1
crw-rw—- 1 root audio 116, 24 2007-12-20 19:40 pcmC0D0c
crw-rw—- 1 root audio 116, 16 2007-12-20 19:40 pcmC0D0p
crw-rw—- 1 root audio 116, 30 2007-12-20 19:40 pcmC0D6c
crw-rw—- 1 root audio 116, 22 2007-12-20 19:40 pcmC0D6p
crw-rw—- 1 root audio 116, 1 2007-12-20 19:40 seq
crw-rw—- 1 root audio 116, 33 2007-12-20 19:40 timer

taufanlubis@toshiba:~$ ls -l /dev/dsp
crw-rw—- 1 root audio 14, 3 2007-12-20 19:40 /dev/dsp
taufanlubis@toshiba:~$ ls -l /dev/mixer
crw-rw—- 1 root audio 14, 0 2007-12-20 19:40 /dev/mixer

Everything is ok.

I have my sound icon back to normal. Test with xmms, …..done….. I can hear the sound again.


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Sometimes I get bored with my login screen. Then I try to figure out, which is the most easy way to change it. Then I came out with this solution. For your information, all your login themes are stored in /usr/share/gdm/themes directory. For default, there are 6 themes that you can choose. You can download from the internet or create your own new one if you want to have more options.

taufanlubis@toshiba:~$ cd /usr/share/gdm/themes
taufanlubis@toshiba:/usr/share/gdm/themes$ ls -l
total 24
drwxr-xr-x 2 root root 4096 2007-12-01 07:54 circles
drwxr-xr-x 2 root root 4096 2007-12-01 07:54 happygnome
drwxr-xr-x 2 root root 4096 2007-12-01 07:54 happygnome-list
drwxr-xr-x 3 root root 4096 2007-12-16 06:33 Human
drwxr-xr-x 2 root root 4096 2007-10-16 06:21 HumanCircle
drwxr-xr-x 3 root root 4096 2007-10-16 06:21 HumanList


You don’t have to change any xml scripts, all you have to do is just choose a theme and replace the background with your one picture. To see the available themes, open System > Administration > Login window then open the Local Tab. For this sample I choose Human theme.


The idea is just replace the background.png with your picture. I suggest to make a copy of original background.png in case you want to use it back. You can’t drag your picture from your directory to /usr/share/gdm/themes/Human directory because you don’t have permissions to write to this folder.


Open Application > Accessories > Terminal.
taufanlubis@toshiba:~$ cd /usr/share/gdm/themes/Human
taufanlubis@toshiba:/usr/share/gdm/themes/Human$ ls -l
total 624
-rw-r–r– 1 root root 387387 2007-12-16 06:33 background.png
-rw-r–r– 1 root root 5910 2007-04-04 16:32 bottom_bar.svg
-rw-r–r– 1 root root 5221 2007-04-04 16:32 boundingbox.svg
-rw-r–r– 1 root root 289 2007-10-12 21:28 GdmGreeterTheme.desktop
drwxr-xr-x 2 root root 4096 2007-10-16 06:21 gtk-2.0
-rw-r–r– 1 root root 4314 2007-04-04 16:32 Human.xml
-rw-r–r– 1 root root 412 2007-04-04 16:32 icon-language-active.png
-rw-r–r– 1 root root 412 2007-04-04 16:32 icon-language.png
-rw-r–r– 1 root root 414 2007-04-04 16:32 icon-language-prelight.png
-rw-r–r– 1 root root 292 2007-04-04 16:32 icon-reboot-active.png
-rw-r–r– 1 root root 316 2007-04-04 16:32 icon-reboot.png
-rw-r–r– 1 root root 295 2007-04-04 16:32 icon-reboot-prelight.png
-rw-r–r– 1 root root 819 2007-04-04 16:32 icon-session-active.png
-rw-r–r– 1 root root 575 2007-04-04 16:32 icon-session.png
-rw-r–r– 1 root root 819 2007-04-04 16:32 icon-session-prelight.png
-rw-r–r– 1 root root 387 2007-04-04 16:32 icon-shutdown-active.png
-rw-r–r– 1 root root 616 2007-04-04 16:32 icon-shutdown.png
-rw-r–r– 1 root root 576 2007-04-04 16:32 icon-shutdown-prelight.png
-rw-r–r– 1 root root 18023 2007-04-04 16:32 screenshot.png
-rw-r–r– 1 root root 134015 2007-04-04 16:32 ubuntu.png
-rw-r–r– 1 root root 2703 2007-04-04 16:32 userentry.svg


Step 1. Create a back up for your background image (if you need it).
taufanlubis@toshiba:/usr/share/gdm/themes/Human$ sudo cp background.png background.png.backup


Step 2. Go to your Picture directory and copy the picture to theme directory to replace the theme background picture.
taufanlubis@toshiba:~/MyData/Pictures/Wallpaper Mac4Linux$ sudo cp Mac-OS-X-Tiger-2-1680×1050.jpg /usr/share/gdm/themes/Human/background.png


Your old file picture file name: Mac-OS-X-Tiger-2-1680×1050.jpg
Your new file name: background.png
The sharpness of the picture will be depend on the pixel size.
That’s it.
Now, you can log out to see your new login screen.


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