Computer Learning, My Free Writing on Computer and Information technology

Looking for some ebook or reference manuals about Mikrotik, i have some of them:

1. Mikrotik peer to peer traffic control
2. Reference Manual of MikroTik RouterOS
3. Tutorial video of MikroTik RouterOS

I hope it will benefits the open source community….

Many softwares can be used to perform Remote Desktop on Ubuntu. One of the best software is NomachineNX. You can see the details of this project by clicking this link, this software is  very interesting since allowing multisession login with different IDs.

NoMachineNX server can be remote controlled from Mac OS, Solaris and Windows. The servers are available for Linux (.rpm .deb and .tar.gz), Solaris. While the clients are available on Linux, Mac OS, Solaris and Windows.

sudo /usr/NX/bin/nxserver --status 

NX> 900 Connecting to server .. NX> 110 NX Server is running. 	 NX> 999 Bye. 

/usr/NX/etc/server.cfg 

ENABLEAUTOKILLSESSIONS = \"1\" ENABLEUNENCRYPTEDSESSION = \"0\" 

ENABLEUNENCRYPTEDSESSION = \"0\" 

/usr/NX/bin/nxlient 

Computer Networking is pervasive right now,you can find it on small company and big enterprise either. Right now i would like to tell a story about computer networking.

First, what computer network is? Most books define it as “a simple collection of computers (two connected computers qualify as a network) at one location that have been tied together using a particular connectivity medium (such as network cabling or wireless technology)”.

The second is why should you need a computer network? It was because network enables anything. The network can be used to transmit data, sound, and even video between users on the network. Many apps such as email and instant messaging are feasible due to computer network.

Computer Network usually consist of computers, connectivity media (eg: as copper wire or fiber optic cables), and other devices (eg: hubs, switches, and routers), and Network interface card. There are many technologies that can bind computers togather, such as network cabling (copper or fiber optics), radio waves, and microwave technology.

If your Linux connected to proxy server, then wget might have problems. To overcome this problem, you have to open /etc/wgetrc using gedit or vi then find text below, just make the use_proxy option to ON and set your http and ftp proxy:
# You can set the default proxies for Wget to use for http and ftp.
# They will override the value in the environment.
http_proxy = http://10.10.1.3:3128/
ftp_proxy = http://10.10.1.3:3128/

# If you do not want to use proxy at all, set this to off.
use_proxy = on
Save the file, and try using wget again.

VNC is one of desktop sharing system that uses RFB protocol that will let us control another computer remotely. VNC can send keyboard and mouse events from one computer to another.

The point of using VNC is that we can control another computer graphically, this will make remote controlling easier than just command based like SSH or Telnet.

Here are steps to install VNC server on Linux so that Linux can be controlled from VNC clients:

First, enable Remote Access (XDMCP) :

• Click System > Administration > Login Window.
• Open Remote tab then choose Same as Local.
• Click Configure XDMCP then uncheck Honor indirect request.
• Open the /etc/X11/gdm/gdm.conf, use gedit or vi.
• Find [xdmcp] on the file then set Enable=True.
• Erase the # in front of RemoteGreeter=/usr/lib/gdm/gdmlogin.
• Now, install vnc4server and xinetd by executing sudo apt-get install vnc4server xinetd.
• Now, create password for VNC by executing command below: sudo vncpasswd /root/.vncpasswd
• Enter password for VNC, for security purpose, you’d better entering password that differ from your system password.

• Now add VNC service into xinetd.by opening /etc/xinetd.d/Xvnc: sudo gedit /etc/xinetd.d/Xvnc Enter this code into that file:file /etc/xinetd.d/Xvnc

service Xvnc
{
type = UNLISTED
disable = no
socket_type = stream
protocol = tcp
wait = yes
user = root
server = /usr/bin/Xvnc
server_args = -inetd :1 -query localhost -geometry 1024?768 -depth 16 -once -fp /usr/share/fonts/X11/misc -DisconnectClients=0 -NeverShared passwordFile=/root/.vncpasswd -extension XFIXES
port = 5901
}

• You could share the screen resolution using your favorite resolusion, eg: 800?600
• Restart xinetd by executing:

sudo /etc/init.d/xinetd stop
sudo killall Xvnc
sudo /etc/init.d/xinetd start

• To test your VNC server, try by executing: vncviewer localhost:1

• If you want to access your VNC server from other computer, you can try TightVNC. It’s multiplatform.

Bridged ADSL connection is better than the pure PPPoE since we can manage the connection easier (we can stop and start the connection without having to open web browser). It’s painless to dial a bridged ADSL connection in Windows, but in Linux, it’s harder. Here are steps you can do to dial up a bridged ADSL connection on Ubuntu Linux:

1. Use pppoeconf, you dont need to install it since it’s already installed on regular Ubuntu installation. just execute 

   #pppoeconf

2. Follow the steps, enter your username and password.
3. Enter your ISP’s DNS nameserver on /etc/resolv.conf
4. To dial the connection use

   # pon dsl-provider

5. To close the connection use

   # poff 

Linux server performing as a samba server for Windows OS clients can be a safe heaven for viruses and other malwares. To overcome this problem, network admin could install anti virus for Linux. The one i admire most is AVG anti virus for Linux that you could download from http://free.grisoft.com
To install it on Ubuntu, you could download the Debian version (.deb). To install .deb installer, you could execute:

sudo dpkg -i avg_version.deb

After that, register your AVG by executing the shell script provided on the end of installation phase. Enter your name and your company name. To activate AVG Anti Virus for Linux, you could click Applications > Accessories > AVG for Linux.

JLan Communicator is a software for chatting on local network. See this picture to know how to chat using JLan Communicator.

First enter your Bind address and Broadcast address. Bind Address is your IP address while the Broadcast address has “255″ suffix.

Click Connect button, and you are ready to chat, just like when chatting @ IRC.

PS: This program needs JRE, just watch for my previous article on how to install JRE.

As a programmer, i did’t know the method to write program’s source codes on Wordpress.com blog. Until recently, after browsing for a while, i finally understand how to write program’s source codes on Wordpress.com blog engine. Just use this code Read the rest of this entry »