Sabtu, 20 Desember 2008

Cracking dan Hacking

Cracking atau Hacking ID atau Username Yahoo Messenger (Termasuk Email): Sekedar Pengantar dan Cara Mengatasinya

Disini saya tidak akan mengajarkan kepada anda mengenai cara-cara cracking id yahoo atau sejenisnya. Disini saya hanya akan memberikan sebuah gambaran umum mengenai cara-cara seseorang melakukan pencurian id atau cracking atau hacking ID yahoo messenger atau email yahoo sekaligus tips singkat mengatasi kejadian atau peristiwa seperti ini.

Cracking ID yahoo dapat dilakukan dengan berbagai cara. Cara yang paling banyak dilakukan adalah dengan menggunakan beberapa tools atau perangkat software crack tertentu. Untuk melakukan kegiatan crack dengan software ini diperlukan pengetahuan dasar mengenai penggunaan proxy maupun koneksitas internet anda. Proxy digunakan untuk me loop atau mengulang percobaan setiap kali crack dilakukan karena amat sangat riskan melakukan cracking tanpa menggunakan proxy atau alat pengaman yang lain. Pengetahuan mengenai penggunaan password juga diperlukan. Dan yang terpenting username yang diperlukan. Melakukan kegiatan cracking juga dilakukan sekaligus untuk beratus-ratus id atau username. Jadi pertama yang dibutuhkan oleh para cracker adalah: list username atau id atau alamat email di yahoo, list password, daftar proxy (ada juga tools yang tidak memerlukan proxy).

Yang saya sebutkan diatas merupakan cara cracking id yahoo lewat tool tertentu. Sedangkan cracking id juga dapat dilakukan dengan cara membuat sebuah website imitasi yang mengharuskan seseorang menuliskan username atau id beserta passwordnya dan kemudian id dan password tersebut dikirim ke sang cracker. Cara ini cukup bermanfaat jika sang pengguna kurang teliti. Untuk lebih membuat cara ini berhasil atau mendapatkan daftar id dan passwordnya biasanya para cracker mengirimkan email peringatan tertentu atau bisa juga mengirimkan pesan atau PM instants message (biasanya berupa spam) ke pengguna yahoo messenger. Tool yang dibutuhkan adalah YM PM spammer atau Yahoo email bombing. Bisa juga dilakukan dengan cara manual

Nah setelah mengetahui dua cara tersebut (masih ada beberapa cara yang lain, tapi yang tersering dan termudah adalah dengan dua cara tersebut), saya ingin memberikan sejumlah tips untuk menghindari hal seperti itu.

Pertama: mengingat yahoo messenger maupun yahoo email merupakan perangkat atau fasilitas yang bersifat gratis atau free maka siapapun dengan mudah dapat menggunakannya dan pihak yahoo tidak begitu memperdulikan jika id email maupun YM anda terkena kegiatan seperti ini. Untuk menghindari cracking cara pertama anda perlu memperkuat password anda seperti sering disarankan. Seperti menggunakan lebih dari 8 karakter. Tidak menggunakan nama anda, tanggal lahir anda, atau menggunakan password dengan kata yang sering digunakan atau yang terdapat dalam kamus. Menggunakan bermacam karakter sekaligus baik itu angka, huruf besar dan kecil serta karakter yang lainnya. Buat tidak berbunyi atau tidak bisa dibaca. (ini menghindari terdapatnya password anda dalam list password cracking mereka.

Yang kedua. Untuk menghindari cara kedua anda musti berhati hati jika ada sebuah email atau private message yang mengarahkan anda untuk menuliskan password yahoo anda. Baik itu dalam bentuk windows private message (PM atau IM) maupun dalam bentuk halaman sebuah situs (webpage).

Yang keempat adalah untuk menghindari lock id ym jangan gunakan email anda untuk keperluan chatting di dunia yahoo messenger.

Yang kelima. Akan lebih baik jika anda menggunakan email yang berbayar atau memiliki reversibilitas (kemampuan layanan balik) yang bagus. Bisa juga dari email perusahaan anda atau institusi anda atau layanan email milik anda sendiri. Dengan cara ini jika terjadi proses cracking dan sang cracker mengganti password anda (ini jika beruntung karena bisa jadi mereka menghancurkan isi mail anda), anda bisa meminta kepada admin atau webmasternya untuk mengembalikan atau memberikan kembali alamat email yang di crack tersebut. Pihak yahoo tidak menyediakan hal ini kepada anda. Anda mau komplain kepada om yahoo, saya yakin akan tidak ditanggapi dan menyuruh membuat account yang baru. Berbahaya bukan. Tapi ini resiko memiliki email gratisan.

WHAT HAPPENS NEXT? THE RAPTURE AND TRIBULATION

WHAT HAPPENS NEXT? THE RAPTURE AND TRIBULATION

RAPTURE (the Biblical term is "caught up" or "translation") is a term used to describe the removal from the earth of all living people that have been born-again, as evidenced by their fruits. Just prior to the Tribulation coming about, the Rapture will take place. The number that will be raptured will be far fewer than most people might think. The Bible unmistakably portrays the raptured saints in heaven before the throne of God, prior to the Antichrist coming forth and the Tribulation beginning. The Scripture tells us, in the twinkling of an eye, we shall be changed and be with Jesus in the air. 1 Cor 15:51,52-WE SHALL NOT ALL SLEEP, BUT WE SHALL ALL BE CHANGED, IN A MOMENT IN THE TWINKLING OF AN EYE, AT THE LAST TRUMP: FOR THE TRUMPET SHALL SOUND; 1 Thes 4:16,17-AND THE DEAD IN CHRIST SHALL RISE FIRST, THEN WE WHICH ARE ALIVE AND REMAIN SHALL BE CAUGHT UP TOGETHER WITH THEM IN THE CLOUDS. We may be asleep, immediately, we will be with Jesus. All the unbelievers, the lukewarm Christians, and those that did not obey the Gospel will be left to face the dreadful Tribulation. (For an in-depth study of the Rapture, click here.)

THE TRIBULATION is the worst time in history since man has been on the earth. Immediately following the Rapture, the man of sin (called the Antichrist) comes forth and assumes control of the EU. He can be expected to be very charismatic and brilliant. He confirms a treaty with Israel and others, which begins the Tribulation.

It is a 7 year period, but the Lord may have shortened the first 3 1/2 years in some way-ref Mk 13:20; Ro 9:28. We are not setting a date; however, we are now living in that generation in which this will happen. Hate, murder, thefts, rape, and every imaginable form of evil will abound. During this horrible period of God’s wrath, Russia, Iran, and other nations will come against Israel. The USA becomes involved. One-fourth of the world’s population will die. Many of the dead will be from the USA, as well as Russia. One-third of trees are burned up. All green grass is burned up. One-third of the sea will become blood. One-third of the creatures in the sea will die. One-third of the ships are destroyed. One-third of the waters become wormwood (or poisoned, or radioactive). Massive famines, increased earthquakes, and more diseases will happen as birth pangs of a woman. Those left alive will have opportunities to receive Jesus through the preaching of 144,000 male, virgin Jews; however, death by decapitation lies ahead for most that put their trust in Jesus, unless they renounce their faith. There will also be many false Christs and false prophets. A one-world, false religion that God calls MYSTERY, BABYLON THE GREAT, THE MOTHER OF HARLOTS AND ABOMINATIONS OF THE EARTH will increase. This religion has existed for hundreds of years and exists today. The nations of the world have become intoxicated with her false teachings. The temple in Jerusalem will be rebuilt.

About 3½ years from the end of the Tribulation, the Antichrist (also called the beast) is killed with a wound in the head by a weapon, but his deadly wound will be healed. He will come back to life. He then declares himself to be God and moves into the temple in Jerusalem. A false prophet appears that will do great wonders. The sacrifices at the temple will be stopped. The abomination of desolation occurs. An image of the Antichrist will be set on a wing of the temple. Those that refuse to worship it will be beheaded. The elect born-again Jews now flee for their lives to a place where God will hide them and take care of them during the last three and a half years. Power is given to the Antichrist over all kindreds, and tongues, and nations. All that dwell on the earth shall worship the Antichrist, whose names are not written in the Lamb's book of life. During these last three and a half years (called the Great Tribulation), world conditions will continue to worsen. A one-world system will exist. The Antichrist shall make war against the saints and will overcome them. People will be required to take the mark of the Antichrist or the number of his name (666) in or on their forehead or right hand. If they, refuse they cannot buy or sell.

Two prophets of God will appear. One of them is Elijah. Their ministry lasts 1260 days. They warn people not to take the mark or worship the image. There is no forgiveness from God afterward for those that do. They will go to the eternal lake of fire. These two witnesses have the power to shut up heaven so that it does not rain. They have the power to bring all kinds of plagues on the earth. Multitudes will be slain for the Word of God. Some type of locusts will sting men with a sting like a scorpion. It will be so bad that men will seek death and shall not find it. There will be terrible sores upon men. The rivers and fountains will become blood. Men will be scorched with great heat. Earthquakes and diseases continue to get worse and worse. Two hundred million troops will march to Israel from the east and cross the dried up Euphrates River. One-third more of the earth’s population will be killed. After the 1260 days, the two prophets of God will be killed. People will rejoice, but then after three and a half days, they will arise and ascend up to heaven as others watch. Great fear falls on those that see this. Men will be so terrified that their hearts will fail, as they consider what is about to happen. Multitudes will hide in the rocks and say, "FALL ON US AND HIDE US FROM...HIM (Jesus)…FOR THE GREAT DAY OF HIS WRATH IS COME; AND WHO SHALL BE ABLE TO STAND?"-Rev 6:16,17.

IMMEDIATELY AFTER THE TRIBULATION of those days, the Battle of Armageddon explodes. It lasts one day. The kings and armies of the earth are gathered to make war against Jesus. Jesus Christ returns as the King of kings and Lord of lords with all His saints. If He had not returned exactly when He did, there should be no life left on earth. The Antichrist and false prophet are cast alive into the lake of fire. Satan is chained for one thousand years, so he can deceive the nations no longer till the thousand years be fulfilled. Every force of nature is likely to be unleashed at once, including killer tornadoes, hurricanes, tidal waves, lightning encircling the earth, and the biggest earthquake in mankind’s history. The cities and the mountains of the world will crumble. The Bible tells that every island fled away. The mountains were not found. There is great hail out of heaven, every stone about the weight of 70 to l00 pounds. The earth will move out of its place. At the end of that one day, there are so few people left alive that a child could list them.

This may all sound like a fairy tale, but remember—from Israel’s rebirth to the Tribulation, there are about 365 prophecies. Incredibly, nearly all have now been fulfilled. In addition, there are over 10,000 prophecies in the Bible and every one up to this time has come true without a single exception. THE FOOL HAS SAID IN HIS HEART THERE IS NO GOD-Ps 14:1.

Apa Yang Akan Terjadi?

WHAT IS GOING ON?

People have said the end was near many times in the past—true. But did you know the Bible shows us no prophecy of the latter days meant anything until Israel was reborn into a nation? Did you know God’s Word indicates to us a generation would not pass from Israel’s rebirth, till all be fulfilled (which includes the Rapture, the Tribulation, and Jesus Christ’s return)? A generation could be as little as 40 years or as much as 70 to 80 years (Note, Parable of the Fig Tree in site menu).

Many people have been preaching about the latter days of the end times in churches, on radio, TV, the Internet and through books and magazines. Some include Billy Graham, Hal Lindsey, Ray Brubaker, John Hagee, Zola Levitt, Jack Van Impe, Peter Lalonde, and Tim LaHaye just to mention a few. To those that understand the Bible, no explanation is needed. To those that are prideful, self-centered, that love this world, that despise God’s correction, that are contentious or seeking the praise of men rather than of God, no explanation is possible-ref Dan 12:4, 10; Mt 24:37, 39.

It has been said that it is virtually impossible for anyone to make 11 straight predictions, 2000 years into the future. There is only one chance in 8 x 10 to the 63rd power, or 80 with 63 zeros after it that such a thing could be done. If such a set of predictions existed, it would have to be the Word of God.

Consider, could you write eleven straight predictions that would take place in the year 4000 A.D.? Include the rebirth of a specific nation and exactly how it would be reborn. Include specific nations that would exist, certain nations that would be allied together, and the exact size of a nation’s army. Include what the people and church would be like. Also include the names of actual cities and name certain crops and fruit trees that would exist. Do eleven straight prophecies and be exactly correct on every single one. The Bible not only does this eleven times, but hundreds of times with absolute, perfect accuracy. If this is so, even the most skeptical person (that is truthful) would have to agree that there is indeed a God and the Bible has to be His Word. 2 Pet 1:20,21-KNOWING THIS FIRST, THAT NO PROPHECY OF THE SCRIPTURE IS OF ANY PRIVATE INTERPRETATION. FOR THE PROPHECY CAME NOT IN OLD TIME BY THE WILL OF MAN: BUT HOLY MEN OF GOD SPAKE AS THEY WERE MOVED BY THE HOLY GHOST. O FOOLS, AND SLOW OF HEART TO BELIEVE ALL THAT THE PROPHETS HAVE SPOKEN-Lk 24:25. However, believing there is a God and acknowledging the Bible is the Word of God does not save a person. A person needs to admit they are a sinner, repent, and receive Jesus Christ as their only hope of being saved. This is done by faith (or trust).

Let's prove the Bible is true and we are nearing the end of the last generation before Christ returns.

1. The Jewish people would be scattered worldwide; yet Israel would become a nation again after a long time and at a time the Bible calls the "latter days"-ref Isa 66:8; Mic 5:3; Ezek 38:8. Against what appeared to be impossible odds, this prophecy has been fulfilled. It happened as predicted on May 14, 1948 after about 2500 years. That’s 1 out of 1.
Note: Israel was destroyed in approximately 721 B.C. and Judah about 135 years later. Since that time, approximately fourteen different peoples have possessed the land of Israel. Yet as the Bible said, the nation of Israel would be reborn.
The rebirth of Israel was a key sign, indicating we had entered a time period called the "latter days." It was the beginning of a countdown leading to the Tribulation and culminating with the Battle of Armageddon and the return of Jesus. Along with the fulfillment of this crucial event are over 360 prophecies that would all come together, so we might recognize that the Tribulation is very close at hand. Some of these are listed here.
Yet the Bible foretells that most people would not believe these things, despite the overwhelming evidence of the signs from God’s Word being fulfilled exactly as predicted. As people refused to believe the flood was coming in Noah’s time, so people today willingly choose to disregard the signs of the times.

2. Israel shall be brought forth in one day, at once-ref Isa 66:8. Prophecy fulfilled-May 14, 1948. That’s 2 out of 2.
Note: On Nov. 29, 1947, the General Assembly of the U.N. approved a resolution calling for the establishment of a Jewish state in Palestine. On the morning of May 14, 1948 (the last day of the British mandate), a meeting of the People’s Council took place in Israel to decide on the name of the state and to finalize the declaration. At precisely 4 pm, the proclamation ceremony began at the Tel Aviv museum. The 979 Hebrew words of the Scroll of Independence were read. All stood, and the scroll was adopted. The notorious White Paper, issued by the British in 1930 restricting Jewish immigration, was declared null and void. Members of the People’s Council signed the proclamation. David Ben-Gurion rapped his gavel, declaring, "The State of Israel is established. This meeting is ended." Israel was brought forth as a nation in one day, at once, exactly as predicted. At midnight, the British soldiers and high commissioner would leave. President Truman was swift in announcing U.S. recognition of Israel. The following morning, on May 15, Israel was under attack by the Egyptian, Syrian, Lebanese, Jordanian, and Iraqi forces.

3. Israel would be brought forth (or reborn) "out of the nations"-Ezek 38:8. Prophecy fulfilled-May 14, 1948. That’s 3 out of 3.
Note: As previously stated, on Nov. 29, 1947, the General Assembly of the "United Nations" approved a resolution calling for the establishment of a Jewish state in Palestine. This prophecy was perfectly fulfilled. Consider, for centuries the land of Israel had been occupied by many nations. Israel was "brought forth out of the nations"—the children of Israel from many nations have been returning to their ancient homeland.

4. Israel must regain the city of Jerusalem-Joel 2:32; Isa 28:14; Ezek 22:19. This happened just as predicted in 1967. That’s 4 out of 4.
Note: The Bible gives us two methods so we would know the time we are in. One is by Israel’s rebirth. The other, by a precise line of events that would all come together at one time. Israel was reborn on May 14th, 1948. The Bible indicates that from Israel’s rebirth a generation would not pass till all be fulfilled. We are not setting any date; however, it seems clear from Israel’s rebirth and the signs of the times— that we are living in the generation in which the Rapture and Tribulation will come and catch most people by surprise. Are you ready?

5. The Christian church at the time of the end would be lukewarm, neither cold nor hot for Jesus. Prophecy fulfilled. That’s 5 out of 5.
Note: God will spew them out. Many ministers and people that call themselves a Christian will not be going to heaven. The Bible tells us—you have acquired wealth, but your true condition is wretched, miserable, poor, blind, and naked, and you don’t know it-Rev 3:14-22. This is today’s church. Most preachers use little Scripture, but lots of worldly stories. Many sing a great deal, but put little emphasis on repentance, obeying, serving, and fearing God, on the fruits of the Spirit, Bible prophecy, water baptism by immersion, and studying your Bible faithfully every day. Many are only entertainment centers that teach what their members want to hear. Many (so-called Christians) are so lukewarm or dead, they don’t even bring their Bibles with them to the house of God. Some famous ministers and Bible schools think this is the best church age ever, yet the Bible clearly shows it is the worst and most deceived.

6. The Bible gives us over 50 descriptions about the people at the time of the end. These fit the people of today perfectly, but did not fit the people of fifty years ago. Here are some:


A. Some would depart from the faith and go into devil worship-1 Tim 4:1. This is perfect.
B. People would mock about the last days and not believe-2 Pe 3:3; Jude 18.
C. People would become lovers of themselves-2 Tim 3:1,2. Remember the TV commercials—"I do it for me"?
D. People would be disobeying their parents-2 Tim 3:1,2.
E. People would be grateful for nothing-2 Tim 3:1,2.
F. Homosexuality would increase-Lk 17:28,30; ref Gen 19:5; Ro 1:24,26,27.
G. People would be without self-control in sex-2 Tim 3:1,2,6; Rev 9:21, Lk 17:28,30; Jude 7. Is this not the great sex generation?
H. People would love pleasures more than God-2 Tim 3:1,2,4. This is true. Shall we go on a picnic, watch football, or sleep. Church?—we can go another time. Our American motto "In God we trust" has become a joke. Remember, these were all predicted centuries ago as part of the signs that we are at the time of the end.
I. People would be taking drugs-Rev 9:21. The Greek word for sorceries, in Rev 9:21, means pharmaceuticals or drugs. God’s Word is 100% right on every one. That’s 6 out of 6. How could you have any doubts at this point?
Note: Fifty years ago, many people seldom locked their doors at night. There was little or no profanity on television, radio, or in the movies. One of the biggest problems in public school was gum chewing. Those days are long gone.

7. There would be weapons that could destroy the world-Mk 13:20; Rev 6:8; Rev 9:18; Zech 14:8,12. Incredibly, this prophecy was written in the days of spears and arrows, yet today it is true. That’s 7 out of 7.
Note: It is estimated that the combined nuclear arsenals of the USA and Russia (as of the year 2007) could kill every living thing on earth 6 times over.

8. The Gospel must be published in all the world-Mk 13:10. This seemingly impossible prophecy was written when there was no printing press, but today it is true. That's 8 out of 8.
Note: In this last generation, to our knowledge, the Gospel is being published (or is about to be published) in the primary language of every nation of the world or "among all nations." In addition, the Gospel is available by short-wave radio nearly everywhere in the world.

9. In the "latter days," when Israel was once again a nation, there would be a great military power to the extreme north of Israel in the land of Magog (which is modern-day Russia)-Ezek 38:2-4,8,15,16. Incredible. That’s 9 out of 9.
Note: How could the Bible have foretold the location of this nation, facts about its military, and even the time period it would come to pass? As was already said, in Lk 24:25-O FOOLS, AND SLOW OF HEART TO BELIEVE ALL THAT THE PROPHETS HAVE SPOKEN.

10. There would be a nation to the far east of Israel, to the end of the earth. This nation would have an army of 200 million. This is astounding. How could the Bible have told the location of a nation and given such a huge figure regarding the size of its army nearly 2000 years ago? China has boasted that they could field an army of this exact figure. That’s 10 out of 10.
11. There would be an economic alliance of the nations of the Old Roman Empire. It would have a military capability. This is an exact description of the European Union today (the EU), which has already adopted the one-currency system for many of their member nations. It is written, IN THE DAYS OF THESE KINGS (these nations, which is now) SHALL THE GOD OF HEAVEN SET UP A KINGDOM-Dan 2:44. That’s 11 out of 11. We have just reached the point that seemed impossible—11 perfect predictions made thousands of years ago—with God nothing is impossible. Certainly, at this point, even the biggest skeptic should see the Bible is true, there is a God, and we are nearing the time of the end.

About 22 prophecies in 11 sets have been given, all perfect and all written centuries ago. The chance that any person could do this 2000 years into the future is not possible. The Bible is the Word of God, and we have just proved it. Believe on the Lord Jesus Christ. Repent and get baptized by full immersion. Read and obey the Gospel. God loves you. He is not willing that any should perish, yet many do. The Rapture is close. Most people are not ready and will not be taken. However, "YOU" cannot say you did not know. Know and understand, Mt 16:26-WHAT IS A MAN PROFITED, IF HE SHALL GAIN THE WHOLE WORLD, AND LOSE HIS OWN SOUL? OR WHAT SHALL A MAN GIVE IN EXCHANGE FOR HIS SOUL? (Note: The Encyclopedia of Bible Prophecy has the complete list of 365 prophecies.)

Selasa, 16 Desember 2008

Ethernet

PENJELASAN ETHERNET
Penjelasan Ethernet
Pengertian Ethernet merupakan jenis skenario perkabelan dan pemrosesan sinyal untuk data jaringan komputer yang dikembangkan oleh Robert Metcalfe dan David Boggs di Xerox Palo Alto Research Center (PARC) pada tahun 1972.
Jenis-jenis Ethernet
Jika dilihat dari kecepatannya, Ethernet terbagi menjadi empat jenis, yakni sebagai berikut:
ü 10 Mbit/detik, yang sering disebut sebagai Ethernet saja (standar yang digunakan: 10Base2, 10Base5, 10BaseT, 10BaseF), spesifikasi IEEE 802.3
ü 100 Mbit/detik, yang sering disebut sebagai Fast Ethernet (standar yang digunakan: 100BaseFX, 100BaseT, 100BaseT4, 100BaseTX), spesifikasi IEEE 802.3u
ü 1000 Mbit/detik atau 1 Gbit/detik, yang sering disebut sebagai Gigabit Ethernet (standar yang digunakan: 1000BaseCX, 1000BaseLX, 1000BaseSX, 1000BaseT), spesifikasi IEEE 802.3z
ü 10000 Mbit/detik atau 10 Gbit/detik. Standar ini belum banyak diimplementasikan.
Cara kerja
Spesifikasi Ethernet mendefinisikan fungsi-fungsi yang terjadi pada lapisan fisik dan lapisan data-link dan cara pembuatan paket data ke dalam frame sebelum ditransmisikan di atas kabel.
Ethernet merupakan sebuah teknologi jaringan yang menggunakan metode transmisi Baseband yang mengirim sinyalnya secara serial 1 bit pada satu waktu. Ethernet beroperasi dalam modus half-duplex, yang berarti setiap station dapat menerima atau mengirim data tapi tidak dapat melakukan keduanya secara sekaligus. Fast Ethernet serta Gigabit Ethernet dapat bekerja dalam modus full-duplex atau half-duplex.
Ethernet menggunakan metode kontrol akses media Carrier Sense Multiple Access with Collision Detection untuk menentukan station mana yang dapat mentransmisikan data pada waktu tertentu melalui media yang digunakan. Dalam jaringan yang menggunakan teknologi Ethernet, setiap komputer akan "mendengar" terlebih dahulu sebelum "berbicara", artinya mereka akan melihat kondisi jaringan apakah tidak ada komputer lain yang sedang mentransmisikan data. Jika tidak ada komputer yang sedang mentransmisikan data, maka setiap komputer yang mau mengirimkan data dapat mencoba untuk mengambil alih jaringan untuk mentransmisikan sinyal. Sehingga, dapat dikatakan bahwa jaringan yang menggunakan teknologi Ethernet adalah jaringan yang dibuat berdasrkan basis First-Come, First-Served, daripada melimpahkan kontrol sinyal kepada Master Station seperti dalam teknologi jaringan lainnya.
Jika dua station hendak mencoba untuk mentransmisikan data pada waktu yang sama, maka kemungkinan akan terjadi collision (kolisi/tabrakan), yang akan mengakibatkan dua station tersebut menghentikan transmisi data, sebelum akhirnya mencoba untuk mengirimkannya lagi pada interval waktu yang acak (yang diukur dengan satuan milidetik). Semakin banyak station dalam sebuah jaringan Ethernet, akan mengakibatkan jumlah kolisi yang semakin besar *** dan kinerja jaringan pun akan menjadi buruk. Kinerja Ethernet yang seharusnya 10 Mbit/detik, jika dalam jaringan terpasang 100 node, umumnya hanya menghasilkan kinerja yang berkisar antara 40% hingga 55% dari bandwidth yang diharapkan (10 Mbit/detik). Salah satu cara untuk menghadapi masalah ini adalah dengan menggunakan Switch Ethernet untuk melakukan segmentasi terhadap jaringan Ethernet ke dalam beberapa collision domain.
Frame Ethernet
Ethernet mentransmisikan data melalui kabel jaringan dalam bentuk paket-paket data yang disebut dengan Ethernet Frame. Sebuah Ethernet frame memiliki ukuran minimum 64 byte, dan maksimum 1518 byte dengan 18 byte di antaranya digunakan sebagai informasi mengenai alamat sumber, alamat tujuan, protokol jaringan yang digunakan, dan beberapa informasi lainnya yang disimpan dalam header serta trailer (footer). Dengan kata lain, maksimum jumlah data yang dapat ditransmisikan (payload) dalam satu buah frame adalah 1500 byte.
Ethernet menggunakan beberapa metode untuk melakukan enkapsulasi paket data menjadi Ethernet frame, yakni sebagai berikut:
Ethernet II (yang digunakan untuk TCP/IP)
Ethernet 802.3 (atau dikenal sebagai Raw 802.3 dalam sistem jaringan Novell, dan digunakan untuk berkomunikasi dengan Novell NetWare versi 3.11 atau yang sebelumnya)
Ethernet 802.2 (juga dikenal sebagai Ethernet 802.3/802.2 without Subnetwork Access Protocol, dan digunakan untuk konektivitas dengan Novell NetWare 3.12 dan selanjutnya)
Ethernet SNAP (juga dikenal sebagai Ethernet 802.3/802.2 with SNAP, dan dibuat sebagai kompatibilitas dengan sistem Macintosh yang menjalankan TCP/IP)
Sayangnya, setiap format frame Ethernet di atas tidak saling cocok/kompatibel satu dengan lainnya, sehingga menyulitkan instalasi jaringan yang bersifat heterogen. Untuk mengatasinya, lakukan konfigurasi terhadap protokol yang digunakan via sistem operasi.
Topologi yang digunakan
Ethernet dapat menggunakan topologi jaringan fisik apa saja (bisa berupa topologi bus, topologi ring, topologi star atau topologi mesh) serta jenis kabel yang digunakan (bisa berupa kabel koaksial (bisa berupa Thicknet atau Thinnet), kabel tembaga (kabel UTP atau kabel STP), atau kabel serat optik). Secara logis, semua jaringan Ethernet menggunakan topologi bus, sehingga satu node akan menaruh sebuah sinyal di atas bus dan sinyal tersebut akan mengalir ke semua node lainnya yang terhubung ke bus

Windows Defender

Windows Pertahanan adalah bagus antispyware gratis aplikasi yang tersedia untuk Windows XP dan merupakan bagian dari Windows Vista. Here’s how to install or uninstall Windows Defender in XP and Vista. Berikut adalah cara menginstal atau menghapus penginstalan Pertahanan di Windows XP dan Vista.

Windows Defender in XP Pertahanan di Windows XP

You can download and install Windows Defender free of charge on the Windows Defender website . Anda dapat men-download dan menginstal Windows Pertahanan gratis pada Windows Pertahanan website.

You’d uninstall Windows Defender just like any other program in Windows XP. Anda uninstall Windows Pertahanan seperti program lain di Windows XP.

Windows Defender in Vista Pertahanan di Windows Vista

Windows Defender is built into Windows Vista and is activated and running by default unless another antivirus software has deactivated it or you choose not to use it during installation. Windows Pertahanan dibangun ke Windows Vista dan diaktifkan dan berjalan dengan standar lain kecuali antivirus telah dinonaktifkan atau Anda memilih untuk tidak menggunakannya selama instalasi.

Turn Windows Defender On ( install ) Pada gilirannya Windows Pertahanan (install)

  1. Open Windows Defender by clicking the Start orb , select All Programs , and the click Windows Defender . Buka Windows Pertahanan dengan mengklik Mulai bulan, pilih Semua Program, dan klik Windows Pertahanan.
  2. Click Turn on and open Windows Defender to activate it. Klik Aktifkan Windows Pertahanan dan terbuka untuk mengaktifkannya.

If you don’t have another antispyware software package running the Windows Security Center will nag you with a balloon warning at the bottom right of your screen. Jika Anda tidak memiliki paket perangkat lunak lain antispyware menjalankan Windows Pusat Keamanan kuda kecil akan Anda dengan balon peringatan di bagian bawah kanan layar Anda. You can click that balloon and then click Turn on now next to Spyware and other malware protection to turn Windows Defender back on. Anda dapat klik yang balon dan kemudian klik Aktifkan sekarang sebelah Spyware dan malware lain perlindungan untuk mengaktifkan kembali pada Windows Pertahanan.


Turn Windows Defender Off ( uninstall ) Belok Windows Pertahanan Tidak aktif (uninstall)

  1. Open Windows Defender by clicking the Start orb , select All Programs , and the click Windows Defender . Buka Windows Pertahanan dengan mengklik Mulai bulan, pilih Semua Program, dan klik Windows Pertahanan.
  2. Click Tools at the top of Windows Defender. Klik Tools di bagian atas Windows Pertahanan.
  3. Click Options . Klik Pilihan.
  4. Scroll down all the way to the bottom and uncheck Use Windows Defender under Administrative options . Tarik ke bawah semua jalan ke bawah dan hilangkan cek pada Use Windows Pertahanan di bawah Administrasi pilihan.

You can turn Windows Defender off instead of uninstalling it just like this in Windows XP also. Anda dapat menghidupkan Windows Pertahanan off bukan menguninstall seperti ini juga di Windows XP.