My Computer related stuff...

Airport Extreme, loosing WAN (adsl2 bridged) unnoticed on regular basis

Labels: adsl2, airport extreme, apple, bug, hardware, network, wifi

posted by Dieter @ 20:41 0 comments

secure synergy

• installed cygwin with openssh on the windows machine.


• put the public ssh-key of my user on laptop into authorized_keys of desktop


• on laptop: ssh desktopuser@desktop -L24801:localhost:24800


• on laptop: synergyc localhost:24801

#!/bin/bash
while /bin/true; do
  for host in worklogin@desktop-work homeuser@imac-home; do
    ssh -L24801:localhost:24800 -f ${host} sleep 5;
    [ ${?} = 0 ] && synergyc --no-restart --no-daemon localhost:24801;
  done
done

#!/bin/bash
# will start proxy-ssh-command in detached screen.

CLIENTNAME=laptopname;

if [ -z "${DISPLAY}" ]; then
  echo "no DISPLAY variable set" >&2;
  exit;
fi

if [ "$( id -n -u )" = "root" ]; then
  SUDO="sudo -u laptopuser ";
  screenname=root_synergy_proxy;
else
  SUDO="";
  screenname=user_synergy_proxy;
fi

case "$(hostname)" in
(${CLIENTNAME}|${CLIENTNAME}\.*)
  proxycommand="while /bin/true; do
    for host in DT1user@desktop1 DT2user@desktop2 DT3user@desktop3; do
      ${SUDO} ssh -L24801:localhost:24800 -f \${host} sleep 5;
      [ \${?} == 0 ] && synergyc --no-restart --no-daemon localhost:24801;
    done;
  done;";
;;
(*)
  # only allow invocation on configured machine.
  echo "this script should only run on ${CLIENTNAME}.">&2;
  exit;
;;
esac

#remove possible defunct screens
screen -wipe

#check for existing (running) screen
screen -list|grep -e '\<[0-9]\{1,\}\.'${screenname}'\>' >/dev/null 2>&1;

case "${?}" in
(0) # depending on existing screen, retrieve it (if requested)
    [ $# -eq 1 ] && [ "$1" = "screen" ] && screen -dr ${screenname};
    ;;
(*) # launch the screen instruction (with screen on console if requested)
    [ $# -eq 1 ] && [ "$1" = "screen" ] && resume="" || resume="-d -m";
    screen ${resume} -S ${screenname} bash -c "${proxycommand}"; 
    ;;
esac;

Labels: cygwin, hardware, network, security

posted by Dieter @ 15:21 1 comments

keyboard and mouse sharing over network

• Start synergy (on windows machine)
  
• select "share this computer's keyboard and mouse"
  
• press "configure" (see image right).
  
  
• press the + button in the screens-section (once for all machines you wish to configure, add the server like this AND all the clients.
  
• in the "Links" section, configure where which display is "logically positioned", so when leaving the display (using the mouse-cursor) at one side, where should it enter (at what side).
  Also provide (if needed) a "return"-link:
  (DON'T THINK that if you configure to leave machine-A through your left-screen-side for the right-screen-side of machine-B, you'll automatically configure the right-side of machine-B to return to the left-side of machine-A, because you don't).
  

• Now you don't have to configure your client, only to launch it and tell it what server to connect. [code]synergyc server[/code] (see man synergyc for extra options).
  

• server to launch automatically (using the "autostart" button on the windows synergy application).
  

• I created a script synergyc_start with the instructions to execute:
  #!/bin/sh
synergyc servername
  
• and added an invocation of that script in /etc/gdm/Init/Default, before the sysmodmap=-line.
  
• and added another invocation of that script in /etc/gdm/PreSession/Default before the XSETROOT=-line.
  

Labels: hardware, linux, network

posted by Dieter @ 14:38 0 comments

Changing MAC address for ethernet card (in linux)

sudo ifconfig eth0 hw internet 00:01:02:03:04:05

Labels: hardware, linux, network

posted by Dieter @ 08:53 0 comments

keyboard Inspiron 8000 (unresponsive [F6]6yhn[F7]7ujm)

• While looking for a solution, I discovered that lifting the machine at its left-front corner (the [ctrl] and [fn]-key corner), and "twisting" the machine a little, could cause the keys to respond again.
• After reading the forum, I also cleaned the keyboard (dismanteled the laptop, blew out the keyboard etc....). After this procedure the problem did not return for about 2 to 3 months. Later occurrences of the problem and then cleaning out the keyboard (even though nothing like dust or spilling was found) resulted in some restoration.
  

Labels: dell, hardware

posted by Dieter @ 14:19 0 comments

Computer Desktop Trouble

• When launching the OS in VGA-modus, (640x480 or 800x600), the problem doesn't occur. Even changing resolution within this VGA modus, is no problem. But as soon as the OS discovers the Video-card and charges its specific driver, the blinking starts and it's no friendly eye-blink (anymore).

• Replacing the hardware graphics adapter (nVidia GeForce 4 for an MSI ATI 9250) didn't solve the problem. Although it seems that ATI doesn't have the problem in lower resolutions, but at 1600x1200 it does.
• The cable between adapter and dispaly doesn't seem to be at fault since the problem occurs both when connected using a VGA- and a DVI-cable.
• The Display (LCD) doesn't seem to be malfunctioning when attached to another system and also running in 1600x1200.
• Even the OS is not at fault since another harddisk was inserted, and a NEW installation from scratch was performed and... once again the blinking starts annoying me.
• A memtest86 of the memory passes without glitch.

• motherboard should be replaced to test its fault, but could be difficult since specific format for the DELL airduct over processor
• processor could be at fault, but don't think so
• memory ... but is expensive to test.
  

Labels: hardware

posted by Dieter @ 13:39 0 comments