Tips tricks Computer Maintenance




To get a stable service from a device we are required to treat the computer as any car that is always on, replaced oil change tires, etc. computer as well as the car that should be given treatments ranging from software, hardware and virus-a virus. Read on to learn what you can do to help improve your computer's security.

Getting started


Here are some basics maintenance tasks you can do today to start improving your computer's security. Be sure you make these part of your ongoing maintenance as well.
  • Sign up for software update e-mail notices. Many software companies will send you e-mail whenever a software update is available. This is particularly important for your operating system (e.g., Microsoft VV!|VD0VV$® or Macintosh), your antivirus program, and your firewall.
  • Register your software. If you still have registration forms for existing software, send them in. And be sure to register new software in the future. This is another way for the software manufacturer to alert you when new updates are available.
  • Install software updates immediately.


When you get an update notice, download the update immediately and install it. (Remember, downloading and installing are two separate tasks.)
An ounce of prevention

A few simple steps will help you keep your files safe and clean.


  • Step 1: Update your software
  • Step 2: Backup your files
  • Step 3: Use antivirus software and keep it updated
  • Step 4: Change your passwords


Developing ongoing maintenance practices


Now that you've done some ground work, it's time to start moving into longer term maintenance tasks. These are all tasks that you should do today (or as soon as possible) to get started. But for best results, make these a part of a regular maintenance schedule. We recommend setting aside time each week to help keep your computer secure.
  • Back up your files. Backing up your files simply means creating a copy of your computer files that you can use in the event the originals are lost. (Accidents can happen.) To learn more read our tips for backing up information.
  • Scan your files with up to date antivirus software. Use your antivirus scan tool regularly to search for potential computer viruses and worms. Also, check your antivirus program's user manual to see if you can schedule an automatic scan of your computer. To learn more, read our tips for reducing your virus risk.
  • Change your passwords. Using the same password increases the odds that someone else will discover it. Change all of your passwords regularly (we recommend monthly) to reduce your risk. Also, choose your passwords carefully. To learn more, read our tips for creating stronger passwords

.

Making a schedule


One of the best ways to help protect your computer is to perform maintenance regularly. To help you keep track, we suggest making a regular "appointment" with your computer. Treat it like you would any other appointment. Record it in your datebook or online calendar, and if you cannot make it, reschedule. Remember, you are not only helping to improve your computer, you are also helping to protect your personal information.




Sumber : Ebooks , Internet
hopefully helpful

Konfigurasi Transparent Proxy Debian Lenny



Assalamu'alaikum Wr.Wb.


Berikut adalah langkah-langkah konfigurasi Transparent Proxy Debian Lenny;

  1. Install Squid

    #apt-get install squid
  2. Stop service squid

    #/etc/init.d/squid stop
  3. Konfigurasi squid

    #vim /etc/squid/squid.conf
  4. Cari kata http_port 3128 kemudian kita tambahkan kata transparent sehingga menjadi:

    #http_port 3128 transparent
  5. Cari kata acl CONNECT kemudian dibawahnya kita tambahkan

    acl url dstdomain "/etc/squid/url"
    acl key url_regex -i "/etc/squid/key"
    no_cache deny url
    no_cache deny key
    http_access deny url
    http_access deny key
  6. Cari kata INSERT YOUR kemudian dibawahnya kita tambahkan

    acl jaringan src ip network/netmask
    http_acces allow jarigan
  7. Cari kata http_access deny all (ada 2)kemudian semuanya di tambah tanda # di depannya
  8. Cari cache_mem 8 M ubah 8 M menjadi 1/4 dari ram PC kemudian hiangkan tanda #
  9. Cari cache_dir ufs /var/spool/squid 10000 16 256
  10. Cari cache_swap_low hilangkan tanda # pada hight dan low
  11. Cari cache_log /var/log/squid/cache.log hilangkan tanda #
  12. Cari cache_store /var/log/squid/store.log hilangkan tanda #
  13. Cari ipcache_size hilangkan tanda # pada size, low ,dan high



Jika ingin mengganti nama administrator yang blok access:    

  • TAG: cache_mgr (nama pengeblok)
    Simpan konfigurasi

Membuat daftar situs yang di blokir

  • #vim /etc/squid/url

    misalkan yang akan diblokir adalah facebook maka ketikkan www.facebook.com setelah selesai membuat daftar situs-situs yang di blokir sipanlah file.


Membuat daftar kata kunci yang di blokir


  • #vim /etc/squid/key
    misalkan kata yang di blokir adalah sex maka ketikkan sex pada daftar an simpan file


Membuat directori swap
  • #squid -z


Menjalankan quid


  • #/etc/init.d/squid. start


Membuat ip tables


  • #iptables -t nat -A PREROUTING -s ipnetworkkamu/netmaskkamu -p tcp --dport 80 -j REDIRECT --to-ports 3128


Supaya settingan tersebut tidak hilang saat komputer restart maka simpan konfigurasi pada rc.local


  • #vim /etc/rc.local
  • diatas exit 0 kita tambahkan
  • iptables -t nat -A PREROUTING -s ipnetworkkamu/netmask -p tcp --dport 80 -j REDIRECT --to-ports 3128
  • Restart squid
    #/etc/init.d/squid restart


Reconfigure squid


  • #squid -k reconfigure
  • Restart networking

    #/etc.init.d/networking restart
  • Jika ingin melihat aktifitas User/client, gunakan Squidview.

    # apt-get install squidview



Nah, itulah beberapa langkah-langkah yang mungkin bisa membantu untuk anda..
Sekian postingan kali ini.. Semoga bermanfaat,

Wassalamu'alaikum Wr.Wb.

Pengertian, Karakteristik, Kelebihan dan Kekurangan Topologi Ring




Assalamu'alaikum Wr.Wb.

 

Topologi Cincin/Ring


  1. Pengertian Topologi Ring


    Topologi cincin adalah topologi jaringan berbentuk rangkaian titik yang masing-masing terhubung ke dua titik lainnya, sedemikian sehingga membentuk jalur melingkar membentuk cincin.

    Pada Topologi cincin, masing-masing titik/node berfungsi sebagai repeater yang akan memperkuat sinyal disepanjang sirkulasinya, artinya masing-masing perangkat saling bekerjasama untuk menerima sinyal dari perangkat sebelumnya kemudian meneruskannya pada perangkat sesudahnya, proses menerima dan meneruskan sinyal data ini dibantu oleh TOKEN.

    TOKEN berisi informasi bersamaan dengan data yang berasal dari komputer sumber, token kemudian akan melewati titik/node dan akan memeriksa apakah informasi data tersebut digunakan oleh titik/node yang bersangkutan, jika ya maka token akan memberikan data yang diminta oleh node untuk kemudian kembali berjalan ke titik/node berikutnya dalam jaringan. Jika tidak maka token akan melewati titik/node sambil membawa data menuju ke titik/node berikutnya. proses ini akan terus berlangsung hingga sinyal data mencapi tujuannya.

    Dengan cara kerja seperti ini maka kekuatan sinyal dalam aliran data dapat terjaga. Kemampuan sinyal data dalam melakukan perjalanan disepanjang lingkaran adalah hal yang sangat vital dalam Topologi cincin.

    Pada topologi cincin, komunikasi data dapat terganggu jika satu titik mengalami gangguan. Jaringan FDDI mengantisipasi kelemahan ini dengan mengirim data searah jarum jam dan berlawanan dengan arah jarum jam secara bersamaan. (Wikipedia).
  2. Karakteristik Topologi Ring


    1. Node-node dihubungkan secara serial di sepanjang kabel dengan bentuk jaringan seperti lingkaran.
    2. Sangat sederhana dalam layout seperti jenis topologi bus.
    3. Paket-paket data dapat mengalir dalam satu arah sehingga tabrakan (collision) dapat dihindarkan.
    4. Masalah yang dihadapi sama dengan topologi bus, yaitu jika salah satu node rusak, maka seluruh jaringan tidak dapat berkomunikasi.
  3. Kelebihan Topologi Ring


    1. Mudah untuk dirancang dan diimplementasikan.
    2. Memiliki performa yang lebih baik daripada topologi bus, bahkan untuk aliran data yang berat sekalipun.
    3. Mudah untuk melakukan konfigurasi ulang dan instalasi perangkat baru.
    4. Mudah untuk melakukan pelacakan dan pengisolasian kesalahan dalam jaringan karena menggunakan konfigurasi point to point.
    5. Hemat kabel.
    6. Tidak akan terjadi tabrakan pengiriman data (collision), karena pada satu waktu hanya satu node yang dapat mengirimkan data.
  4. Kekurangan


    1. Peka kesalahan, sehingga jika terdapat gangguan di suatu node mengakibatkan terganggunya seluruh jaringan. Namun hal ini dapat diantisipasi dengan menggunakan cincin ganda (dual ring).
    2. Pengembangan jaringan lebih kaku, karena memindahkan, menambah dan mengubah perangkat jaringan dan mempengaruhi keseluruhan jaringan.
    3. Kinerja komunikasi dalam jaringan sangat tergantung pada jumlah titik/node yang terdapat pada jaringan.
    4. Lebih sulit untuk dikonfigurasi daripada Topologi bintang.
    5. Diperlukan penanganan dan pengelolaan khusus bandles.


Sekian Postingan Kali ini.. Semoga bermanfaat
Sumber : Wikipedia dan File doc.

Wassalamu'alaikum Wr.Wb.

A Basic To The Internet



The Internet is a computer network made up of thousands of networks worldwide. No one knows exactly how many computers are connected to the Internet. It is certain, however, that these number in the millions.

No one is in charge of the Internet. There are organizations which develop technical aspects of this network and set standards for creating applications on it, but no governing body is in control. The Internet backbone, through which Internet traffic flows, is owned by private companies.

All computers on the Internet communicate with one another using the Transmission Control Protocol/Internet Protocol suite, abbreviated to TCP/IP. Computers on the Internet use a client/server architecture. This means that the remote server machine provides files and services to the user's local client machine. Software can be installed on a client computer to take advantage of the latest access technology.

An Internet user has access to a wide variety of services: electronic mail, file transfer, vast information resources, interest group membership, interactive collaboration, multimedia displays, real-time broadcasting, shopping opportunities, breaking news, and much more.

The Internet consists primarily of a variety of access protocols. Many of these protocols feature programs that allow users to search for and retrieve material made available by the protocol.

COMPONENTS OF THE INTERNET


  1. WORLD WIDE WEB
    The World Wide Web (abbreviated as the Web or WWW) is a system of Internet servers that supports hypertext to access several Internet protocols on a single interface. Almost every protocol type available on the Internet is accessible on the Web. This includes e-mail, FTP, Telnet, and Usenet News. In addition to these, the World Wide Web has its own protocol: HyperText Transfer Protocol, or HTTP. These protocols will be explained later in this document.

    The World Wide Web provides a single interface for accessing all these protocols. This creates a convenient and user-friendly environment. It is no longer necessary to be conversant in these protocols within separate, command-level environments. The Web gathers together these protocols into a single system. Because of this feature, and because of the Web's ability to work with multimedia and advanced programming languages, the Web is the fastest-growing component of the Internet.

    The operation of the Web relies primarily on hypertext as its means of information retrieval. HyperText is a document containing words that connect to other documents. These words are called links and are selectable by the user. A single hypertext document can contain links to many documents. In the context of the Web, words or graphics may serve as links to other documents, images, video, and sound. Links may or may not follow a logical path, as each connection is programmed by the creator of the source document. Overall, the Web contains a complex virtual web of connections among a vast number of documents, graphics, videos, and sounds.

    Producing hypertext for the Web is accomplished by creating documents with a language called HyperText Markup Language, or HTML. With HTML, tags are placed within the text to accomplish document formatting, visual features such as font size, italics and bold, and the creation of hypertext links. Graphics and multimedia may also be incorporated into an HTML document. HTML is an evolving language, with new tags being added as each upgrade of the language is developed and released. The World Wide Web Consortium (W3C), led by Web founder Tim Berners-Lee, coordinates the efforts of standardizing HTML. The W3C now calls the language XHTML and considers it to be an application of the XML language standard.

    The World Wide Web consists of files, called pages or home pages, containing links to documents and resources throughout the Internet.

    The Web provides a vast array of experiences including multimedia presentations, real-time collaboration, interactive pages, radio and television broadcasts, and the automatic "push" of information to a client computer. Programming languages such as Java, JavaScript, Visual Basic, Cold Fusion and XML are extending the capabilities of the Web. A growing amount of information on the Web is served dynamically from content stored in databases. The Web is therefore not a fixed entity, but one that is in a constant state of development and flux.

    For more complete information about the World Wide Web, see Understanding The World Wide Web.

  2. E-MAIL
    Electronic mail, or e-mail, allows computer users locally and worldwide to exchange messages. Each user of e-mail has a mailbox address to which messages are sent. Messages sent through e-mail can arrive within a matter of seconds.

    A powerful aspect of e-mail is the option to send electronic files to a person's e-mail address. Non-ASCII files, known as binary files, may be attached to e-mail messages. These files are referred to as MIME attachments.

    MIME stands for Multimedia Internet Mail Extension, and was developed to help e-mail software handle a variety of file types. For example, a document created in Microsoft Word can be attached to an e-mail message and retrieved by the recipient with the appropriate e-mail program. Many e-mail programs, including Eudora, Netscape messenger, and Microsoft Outlook, offer the ability to read files written in HTML, which is itself a MIME type.
  3. TELNET
    Telnet is a program that allows you to log into computers on the Internet and use online databases, library catalogs, chat services, and more. There are no graphics in Telnet sessions, just text. To Telnet to a computer, you must know its address. This can consist of words (locis.loc.gov) or numbers (140.147.254.3). Some services require you to connect to a specific port on the remote computer. In this case, type the port number after the Internet address. Example: telnet nri.reston.va.us 185.

    Telnet is available on the World Wide Web. Probably the most common Web-based resources available through Telnet have been library catalogs, though most catalogs have since migrated to the Web. A link to a Telnet resource may look like any other link, but it will launch a Telnet session to make the connection. A Telnet program must be installed on your local computer and configured to your Web browser in order to work.

    With the increasing popularity of the Web, Telnet has become less frequently used as a means of access to information on the Internet.
  4. FTP
    FTP stands for File Transfer Protocol. This is both a program and the method used to transfer files between computers. Anonymous FTP is an option that allows users to transfer files from thousands of host computers on the Internet to their personal computer account. FTP sites contain books, articles, software, games, images, sounds, multimedia, course work, data sets, and more.

    If your computer is directly connected to the Internet via an Ethernet cable, you can use one of several PC software programs, such as WS_FTP for Windows, to conduct a file transfer.

    FTP transfers can be performed on the World Wide Web without the need for special software. In this case, the Web browser will suffice. Whenever you download software from a Web site to your local machine, you are using FTP. You can also retrieve FTP files via search engines such as FtpFind, located at /http://www.ftpfind.com/. This option is easiest because you do not need to know FTP program commands.
  5. E-MAIL DISCUSSION GROUPS
    One of the benefits of the Internet is the opportunity it offers to people worldwide to communicate via e-mail. The Internet is home to a large community of individuals who carry out active discussions organized around topic-oriented forums distributed by e-mail. These are administered by software programs. Probably the most common program is the listserv.

    A great variety of topics are covered by listservs, many of them academic in nature. When you subscribe to a listserv, messages from other subscribers are automatically sent to your electronic mailbox. You subscribe to a listserv by sending an e-mail message to a computer program called a listserver. Listservers are located on computer networks throughout the world. This program handles subscription information and distributes messages to and from subscribers. You must have a e-mail account to participate in a listserv discussion group. Visit Tile.net at /http://tile.net/ to see an example of a site that offers a searchablecollection of e-mail discussion groups.

    Majordomo and Listproc are two other programs that administer e-mail discussion groups. The commands for subscribing to and managing your list memberships are similar to those of listserv.
  6. USENET NEWS
    Usenet News is a global electronic bulletin board system in which millions of computer users exchange information on a vast range of topics. The major difference between Usenet News and e-mail discussion groups is the fact that Usenet messages are stored on central computers, and users must connect to these computers to read or download the messages posted to these groups. This is distinct from e-mail distribution, in which messages arrive in the electronic mailboxes of each list member.

    Usenet itself is a set of machines that exchanges messages, or articles, from Usenet discussion forums, called newsgroups. Usenet administrators control their own sites, and decide which (if any) newsgroups to sponsor and which remote newsgroups to allow into the system.

    There are thousands of Usenet newsgroups in existence. While many are academic in nature, numerous newsgroups are organized around recreational topics. Much serious computer-related work takes place in Usenet discussions. A small number of e-mail discussion groups also exist as Usenet newsgroups.

    The Usenet newsfeed can be read by a variety of newsreader software programs. For example, the Netscape suite comes with a newsreader program called Messenger. Newsreaders are also available as standalone products.
  7. FAQ, RFC, FYI
    FAQ stands for Frequently Asked Questions. These are periodic postings to Usenet newsgroups that contain a wealth of information related to the topic of the newsgroup. Many FAQs are quite extensive. FAQs are available by subscribing to individual Usenet newsgroups. A Web-based collection of FAQ resources has been collected by The Internet FAQ Consortium and is available at /http://www.faqs.org/.

    RFC stands for Request for Comments. These are documents created by and distributed to the Internet community to help define the nuts and bolts of the Internet. They contain both technical specifications and general information.

    FYI stands for For Your Information. These notes are a subset of RFCs and contain information of interest to new Internet users.

    Links to indexes of all three of these information resources are available on the University Libraries Web site at /http://library.albany.edu/reference/faqs.html.
  8. CHAT & INSTANT MESSENGING
    Chat programs allow users on the Internet to communicate with each other by typing in real time. They are sometimes included as a feature of a Web site, where users can log into the "chat room" to exchange comments and information about the topics addressed on the site. Chat may take other, more wide-ranging forms. For example, America Online is well known for sponsoring a number of topical chat rooms.

    Internet Relay Chat (IRC) is a service through which participants can communicate to each other on hundreds of channels. These channels are usually based on specific topics. While many topics are frivolous, substantive conversations are also taking place. To access IRC, you must use an IRC software program.

    A variation of chat is the phenomenon of instant messenging. With instant messenging, a user on the Web can contact another user currently logged in and type a conversation. Most famous is America Online's Instant Messenger. ICQ, MSN and Yahoo are other commonly-used chat programs.

    Other types of real-time communication are addressed in the tutorial Understanding the World Wide Web.
  9. MUD/MUSH/MOO/MUCK/DUM/MUSE

    MUD stands for Multi User Dimension. MUDs, and their variations listed above, are multi-user virtual reality games based on simulated worlds. Traditionally text based, graphical MUDs now exist. There are MUDs of all kinds on the Internet, and many can be joined free of charge. For more information, read one of the FAQs devoted to MUDs available at the FAQ site at.

Sumber : Ebooks
hopefully helpful

Beep Codes Error Codes



The computer POST (power-on self-test) checks a computer's internal hardware for compatibility and connection before starting the remainder of the boot process. If the computer passes the POST, the computer may give a single beep (some computers may beep twice) as it starts and continue to boot. However, if the computer fails the POST, the computer will either not beep or generate a beep code that tells the user the source of the problem.

Standard Original IBM POST Error Codes


Code Description

  • 1 short beep System is OK
  • 2 short beeps POST Error - error code shown on screen No beep Power supply or system board problem Continuous beep Power supply, system board, or keyboard problem Repeating short beeps Power supply or system board problem
  • 1 long, 1 short beep System board problem
  • 1 long, 2 short beeps Display adapter problem (MDA, CGA)
  • 1 long, 3 short beeps Display adapter problem (EGA)
  • 3 long beeps 3270 keyboard card


Code Description

  • 100 - 199 System Board
  • 200 - 299 Memory
  • 300 - 399 Keyboard
  • 400 - 499 Monochrome Display
  • 500 - 599 Colour/Graphics Display
  • 600 - 699 Floppy-disk drive and/or Adapter
  • 700 - 799 Math Coprocessor
  • 900 - 999 Parallel Printer Port
  • 1000 - 1099 Alternate Printer Adapter
  • 1100 - 1299 Asynchronous Communication Device, Adapter, or Port
  • 1300 - 1399 Game Port
  • 1400 - 1499 Colour/Graphics Printer
  • 1500 - 1599 Synchronous Communication Device, Adapter, or Port
  • 1700 - 1799 Hard Drive and/or Adapter
  • 1800 - 1899 Expansion Unit (XT)
  • 2000 - 2199 Bisynchronous Communication Adapter
  • 2400 - 2599 EGA system-board Video (MCA)
  • 3000 - 3199 LAN Adapter
  • 4800 - 4999 Internal Modem
  • 7000 - 7099 Phoenix BIOS Chips
  • 7300 - 7399 3.5" Disk Drive
  • 8900 - 8999 MIDI Adapter
  • 11200 - 11299 SCSI Adapter
  • 21000 - 21099 SCSI Fixed Disk and Controller
  • 21500 - 21599 SCSI CD-ROM System

AMI BIOS Beep Codes

Code Description

  • 1 Short Beep System OK
  • 2 Short Beeps Parity error in the first 64 KB of memory
  • 3 Short Beeps Memory failure in the first 64 KB
  • 4 Short Beeps Memory failure in the first 64 KB Operational of memory
  • or Timer 1 on the motherboard is not functioning
  • 5 Short Beeps The CPU on the motherboard generated an error
  • 6 Short Beeps The keyboard controller may be bad. The BIOS cannot switch to protected mode
  • 7 Short Beeps The CPU generated an exception interrupt
  • 8 Short Beeps The system video adapter is either missing, or its memory is faulty
  • 9 Short Beeps The ROM checksum value does not match the value encoded in the BIOS
  • 10 Short Beeps The shutdown register for CMOS RAM failed
  • 11 Short Beeps The external cache is faulty
  • 1 Long, 3 Short Beeps Memory Problems
  • 1 Long, 8 Short Beeps Video Card Problems

Phoenix BIOS Beep Codes

Note - Phoenix BIOS emits three sets of beeps, separated by a brief pause.

Code Description

  • 1-1-3 CMOS read/write failure
  • 1-1-4 ROM BIOS checksum error
  • 1-2-1 Programmable interval timer failure
  • 1-2-2 DMA initialisation failure
  • 1-2-3 DMA page register read/write failure
  • 1-3-1 RAM refresh verification failure
  • 1-3-3 First 64k RAM chip or data line failure
  • 1-3-4 First 64k RAM odd/even logic failure
  • 1-4-1 Address line failure first 64k RAM
  • 1-4-2 Parity failure first 64k RAM
  • 2-_-_ Faulty Memory
  • 3-1-_ Faulty Motherboard
  • 3-2-4 Keyboard controller Test failure
  • 3-3-4 Screen initialisation failure
  • 3-4-1 Screen retrace test failure
  • 3-4-2 Search for video ROM in progress
  • 4-2-1 Timer tick interrupt in progress or failure
  • 4-2-2 Shutdown test in progress or failure
  • 4-2-3 Gate A20 failure
  • 4-2-4 Unexpected interrupt in protected mode
  • 4-3-1 RAM test in progress or failure>ffffh
  • 4-3-2 Faulty Motherboard
  • 4-3-3 Interval timer channel 2 test or failure
  • 4-3-4 Time of Day clock test failure
  • 4-4-1 Serial port test or failure
  • 4-4-2 Parallel port test or failure
  • 4-4-3 Math coprocessor test or failure
  • Low 1-1-2 System Board select failure
  • Low 1-1-3 Extended CMOS RAM failure 
Sumber : Ebooks
hopefully helpful

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