VNC (Virtual Network Computing)

VNC is software that is used for remote desktop application. An engineer from JDSU introduced me to VNC. We can use VNC to control another desktop. It is very simple, just connect your desktop and remote desktop with cross cable and play your VNC. In VNC application you just need to fill IP address, Subnet, and DNS of your remote desktop. After that... you can control your remote desktop easily.

To install VNC it is very easy as well. It has its free edition.

I use VNC to control Optical DWDM Analyzer. I use JDSU. It is a kind of Optical spectrum analyzer that is specially designed for DWDM measurement. We an use USB memory stick to copy measurement result and process it in our desktop. But... it is very risky. Why? USB memory stick is potential to spead virus to our analyzer. So, i prefer to use VNC to display the result and capture the result by "print screen-ing" it.

About "print screen-ing" i will talk later. It uses a special software : SNAGIT.

Buy Gold Now for Your Future!

What poor man do if he get a million dollar? He will spend his money for electronic equipment, new car, vacation, and think hard how to spend his money.

What rich man do if he get a million dollar? He will think the way to "reproduce" the money. He never think to spend his money except for his primary and secondary needs. What in his mind is investation!!!

I hope you get the point of my explanation above. Rich man thinks how to get more money from small amount of money. The answer is investation. The real rich man will invest his money into gold. He will buy gold coin or buy gold bullion. The one who buy gold coin is one who loves about art. For the one who don't care about art, he will purchase gold bullion. For him, the most important thing is the value of the gold. Art is not important. Either buy gold coin or buy bullion
is better than buying jewelery. Why? Although they are the same gold, you must pay more for production cost of jewelery. Another weakness of jewelery is selling price is lower than buying price. In the other word you will loss some money when you sell your jewelery.

So.. what are you waiting for. Buy gold coin , buy gold bullion now! For a better future!

Online Course in ITU Academy

Now you can join vairous online course about telecommunication in :

http://academy.itu.int/

To enroll the course you must obtain enrollment key. How to get enrollment key?
ITU usually invites particular enterprise or government institution to join the course. It gives enrollment key to the ones which are invited.

Direct TV

DirecTV provides television and audio services to subscribers through satellite transmissions. Services include the equivalent of many local television stations, broadcast television networks, subscription television services, satellite radio services, and private video services. Subscribers have access to dozens or hundreds of channels, so its competitors are cable television service and other satellite-based services

Consumers who purchased DirecTV equipment subscribe to various packages of DirecTV programming for which the subscriber pays a monthly fee. A subscriber also can order pay-per-view events and movies. DirecTV contracts with and pays program providers such as cable networks, motion picture distributors, sports leagues, event promoters, and other programming rights holders, for the right to distribute their programming to its subscribers. All programming distributed by DirecTV is delivered to its broadcast centers in Castle Rock, Colorado, and Los Angeles, California, where it is then digitized and compressed. The resulting signal is encrypted, or electronically scrambled, by DirecTV to prevent its unauthorized reception. DirecTV then transmits these signals to several satellites located in stationary orbit approximately 22,300 miles above the equator

Blue Screen

Yesterday, i've got my laptop underwent 'blue screen'
Anybody knows what it is?

Let u s check the answer. I took this from wikipedia :

The Blue Screen of Death (also known as a stop error, BSoD, bluescreen, or Blue Screen of Doom) is a colloquialism used for the error screen displayed by some operating systems, most notably Microsoft Windows, after encountering a critical system error which can cause the system to shut down to prevent damage.

Bluescreens on NT-based Windows systems are usually caused by poorly-written device drivers or malfunctioning hardware. In the Win9x era, incompatible DLLs or bugs in the kernel of the operating system could also cause bluescreens. They can also be caused by physical faults such as faulty memory, power supplies, overheating of computer components, or hardware running beyond its specification limits. Bluescreens have been present in all Windows-based operating systems since Windows 3.1; earlier, OS/2 suffered the Black Screen of Death, and early builds of Windows Vista displayed the Red Screen of Death after a boot loader error.

Understanding Mac Address Flooding

In a typical MAC flooding attack, a switch is flooded with packets, each containing different source MAC addresses. The intention is to consume the limited memory set aside in the switch to store the MAC address-to-physical port translation table.

The result of this attack causes the switch to enter a state called failopen mode, in which all incoming packets are broadcast out on all ports (as with a hub), instead of just down the correct port as per normal operation. A malicious user could then use a packet sniffer running in promiscuous mode to capture sensitive data from other computers, which would not be accessible were the switch operating normally.

Cisco gives you an opportunity to set up protection against this attack with limiting and/or hardwiring some MAC addresses to a dedicated port.

Understand the MAC flooding attack
Suppose to have a switch with 3 PC: PC A, PC B and PC C; in normal situation, when PC A sends a packet to PC B, PC C does not view packet sent between PC A and PC B.

This because the 3 PC are connected to a switch and NOT to a hub.

Under MAC flooding attack, the switch behaviour is different. During the MAC flooding attack, the attacker (in this instance PC C) floods the switch with packets, each with different source MAC address.

If the Content Addressable Memory (the memory where the MAC addresses are stored) is full, the switch works like an hub; so, if the PC A sends a packet to PC B, the packet will be received to PC C too.

802.1x

What is 802.1x?

"Port-based network access control makes use of the physical access characteristics of IEEE 802 LAN infrastructures in order to provide a means of authenticating and authorizing devices attached to a LAN port that has point-to-point connection characteristics, and of preventing access to that port in cases which the authentication and authorization fails. A port in this context is a single point of attachment to the LAN infrastructure." --- 802.1X-2001, page 1.


Figure 802.1X: A wireless node must be authenticated before it can gain access to other LAN resources

1. When a new wireless node (WN) requests access to a LAN resource, the access point (AP) asks for the WN's identity. No other traffic than EAP is allowed before the WN is authenticated (the "port" is closed).

   The wireless node that requests authentication is often called Supplicant, although it is more correct to say that the wireless node contains a Supplicant. The Supplicant is responsible for responding to Authenticator data that will establish its credentials. The same goes for the access point; the Authenticator is not the access point. Rather, the access point contains an Authenticator. The Authenticator does not even need to be in the access point; it can be an external component.

   EAP, which is the protocol used for authentication, was originally used for dial-up PPP. The identity was the username, and either PAP or CHAP authentication [RFC1994] was used to check the user's password. Since the identity is sent in clear (not encrypted), a malicious sniffer may learn the user's identity. "Identity hiding" is therefore used; the real identity is not sent before the encrypted TLS tunnel is up.

2. After the identity has been sent, the authentication process begins. The protocol used between the Supplicant and the Authenticator is EAP, or, more correctly, EAP encapsulation over LAN (EAPOL). The Authenticator re-encapsulates the EAP messages to RADIUS format, and passes them to the Authentication Server.

   During authentication, the Authenticator just relays packets between the Supplicant and the Authentication Server. When the authentication process finishes, the Authentication Server sends a success message (or failure, if the authentication failed). The Authenticator then opens the "port" for the Supplicant.

3. After a successful authentication, the Supplicant is granted access to other LAN resources/Internet.

Sumber : http://tldp.org/HOWTO/html_single/8021X-HOWTO/