Basic MPLS

Multiprotocol Label Switching (MPLS) has evolved from being a buzzword in the networking industry to a widely deployed technology in service provider (SP) networks. In recent years, MPLS has also been adopted by the enterprise and federal market segments. MPLS is a contemporary solution to address a multitude of problems faced by present-day networks: speed, scalability, quality of service (QoS) management, and traffic engineering. Service providers are realizing larger revenues by the implementation of service models based on the flexibility and value adds provided by MPLS solutions. MPLS also provides an elegant solution to satisfy the bandwidth management and service requirements for next-generation IP–based backbone networks.

Unicast IP Forwarding in Traditional IP Networks

In traditional IP networks, routing protocols are used to distribute Layer 3 routing information. depicts a traditional IP network where network layer reachability information (NLRI) for network 172.16.10.0/24 is propagated using an IP routing protocol. Regardless of the routing protocol, packet forwarding is based on the destination address alone. Therefore, when a packet is received by the router, it determines the next-hop address using the packet's destination IP address along with the information from its own forwarding/routing table. This process of determining the next hop is repeated at each hop (router) from the source to the destination except in the case of policy-based routing where a certain outbound policy might affect packet forwarding

1.	R4 receives a data packet destined for 172.16.10.0 network.
2.	R4 performs route lookup for 172.16.10.0 network in the forwarding table, and the packet is forwarded to the next-hop Router R3.
3.	R3 receives the data packet with destination 172.16.10.0, performs a route lookup for 172.16.10.0 network, and forwards the packet to next-hop Router R2.
4.	R2 receives the data packet with destination 172.16.10.0, performs a route lookup for 172.16.10.0 network, and forwards the packet to next-hop Router R1.

Because R1 is directly connected to network 172.16.10.0, the router forwards the packet on to the appropriate connected interface.

MPLS Forwarding

In MPLS enabled networks, packets are forwarded based on labels. These labels might correspond to IP destination addresses or to other parameters, such as QoS classes and source address. Labels are generated per router (and in some cases, per interface on a router) and bear local significance to the router generating them. Routers assign labels to define paths called Label Switched Paths (LSP) between endpoints. Because of this, only the routers on the edge of the MPLS network perform a routing lookup.

illustrates the same network as depicted in Figure 1-1 with MPLS forwarding where route table lookups are performed only by MPLS edge border routers, R1 and R4. The routers in MPLS network R1, R2, and R3 propagate updates for 172.16.10.0/24 network via an IGP routing protocol just like in traditional IP networks, assuming no filters or summarizations are not configured. This leads to the creation of an IP forwarding table. Also, because the links connecting the routers are MPLS enabled, they assign local labels for destination 172.16.10.0 and propagate them upstream to their directly connected peers using a label distribution protocol; for example, R1 assigns a local label L1 and propagates it to the upstream neighbor R2. R2 and R3 similarly assign labels and propagate the same to upstream neighbors R3 and R4, respectively. Consequently, as illustrated in, the routers now maintain a label forwarding table to enable labeled packet forwarding in addition to the IP routing table. The concept of upstream and downstream is explained in greater detail in the section.

Start Learn CCIP

• Basic MPLS
• MPLS VPNs with Static Routing
• MPLS VPNs with RIPv2
• MPLS VPNs with OSPF
• MPLS VPNs with EIGRP
• MPLS VPNs with EBGP

Tips: Menghapus virus di USB flash disk

Biasanya flash disk yang kena virus seperti virus Agnes, Dian Sastro tidak bisa dihapus dengan menggunakan tombol Delete atau kombinasi Shift + Delete di Windows.

Tapi ada cara tertentu untuk membasminya :

1. Buka Command Prompt
2. Ketik cd\
3. Ketik flash disk berada misalkan flash disk di drive D berarti ketik "D:" (tanpa tanda kutip)
4. Ketik del *.* atau dengan format D: tekan Enter.

Apabila anda menggunakan Format D: berarti data terlebih dahulu di Backup. Semoga artikel ini berguna.

Tips: Mengamankan web server IIS

Internet Information Server (IIS) adalah sebuah web server yang tersedia secara otomatis pada saat instalasi Windows edisi server dengan opsi Typical atau Full. Sayangnya instalasi default ini dapat mengakibatkan celah keamanan di sistem anda yang berakibat fatal. Bagaimana cara mengamankannya?

Web server adalah inti dari organisasi internet yang komplek saat ini. Setiap kali sebuah browser berhubungan dengan suatu situs web baik di internet ataupun intranet, maka ia terhubung dengan web server, server tersebut mendengarkan request pada jaringan dan menjawabnya kepada client atau pengirim permintaan dengan membawa data tertentu.

IIS atau yang dikenal dengan Internet Information Server adalah web server yang secara default terinstall saat kita menginstalasi secara tipikal suatu server windows.

IIS menginstal dirinya sendiri kepada partisi primer secara automatis. Ini menyebabkan suatu resiko keamanan sendiri, sebab User Internet dapat mengakses partisi sistem setiap kali mereka melihat suatu Halaman web atau menggunakan FTP untuk download suatu file.

Dibawah ini adalah daftar direktori yang dibuatkan default oleh IIS:
- %WinDir%\InetPub
- %WinDir%\System32\InetSrv
- %WinDir%\System32\InetSrv\IisAdmin
- %WinDir%\Help\IISHelp

IIS menciptakan dua akun user selama instalasi: IUSR_COMPUTERNAME dan IWAM_COMPUTERNAME. IIS menggantikan variabel "computername" dengan nama komputer kita.

Contoh, jika kita sedang menginstall IIS dan nama komputer kita "BAPUK", Maka akun komputer adalah IUSR_BAPUK dan IWAM_BAPUK. Hebatnya lagi akun tersebut tidak bisa dihapus, karena IIS memerlukannya. Akun IUSR_COMPUTERNAME digunakan untuk mengijinkan akses tanpa nama atau "Anonymous" kedalam sistem, sedang akun IWAM_COMPUTERNAME digunakan untuk menjalankan out-of-process dari aplikasi web.

Tidak setiap server windows memerlukan IIS sebagai webservernya. IIS sendiri seharusnya tidak diinstall dalam keadaan default, bila tetap memerlukan IIS ada baiknya mengubah default partisinya agar tidak sama dengan partisi sistem anda. Agar apa? ya itu tadi untuk keamanan.

Apabila IIS telah terinstall sebaiknya anda menguninstall dan reinstall lagi IIS pada partisi yang kita inginkan.

Bagaimana mengubahnya ke partisi yang kita inginkan sedang tak ada pilihan sewaktu instalasinya? Memang tidak ada cara mengubah direktori "program files" pada "Add/Remove program wizard". Untuk mengubahnya kita harus membuat sebuah "answer file" lalu menginstallnya.

Apa itu answer file? Bagaimana cara membuatnya? "Answer File" atau file jawaban kurang lebih adalah suatu file teks yang digunakan untuk mem-bypass / melewati suatu prosedur instalasi secara normal.

Tabel dibawah adalah beberapa komponen IIS yang diperlukan dalam membuat "answer file":

-----------------------------------------------------------
Sintak        =>Tujuan                                       
-----------------------------------------------------------          
iis_common    => Install "common file"                           
iis_doc       => Install dokumentasi IIS
iis_ftp       => Install Service FTP                              
Iis_htmla     => Install "Web-based administration tools"           
iis_inetmgr   => Install "MMC-based administration tools"           
iis_nntp_docs => Install dokumentasi NNTP
iis_smtp      => Install Service SMTP                             
iis_smtp_docs => Install dokumentasi SMTP
iis_www       => Install Service WWW                           
-----------------------------------------------------------

Untuk prosedur penggunaannya silahkan ikuti tutorial berikut:

1. Kilk menu Start > Run
2. Ketik notepad dalam kotak dialognya lalu klik OK
3. Ikuti sintak berikut yang disesuaikan dengan "table komponen answer file" di atas: [Components] iis_common = on
   iis_ftp = on
   iis_htmla = on
   iis_www = on
   [InternetServer]
   PathFTPRoot= D:\Inetpub\Ftproot
   PathWWWRoot=D:\Inetpub\Wwwroot
   (D: Menunjukan letak partisi yang diinginkan untuk lokasi IIS.)
4. Simpan file tadi di direktori C:\ dengan nama iis.txt atau terserah anda.

Setelah membuat file jawaban tadi, berarti kita hampir siap untuk melakukan instalasi. Kenapa hampir? yup..karena kita memerlukan satu program lagi yang digunakan untuk menginstalisasi dari "answer file" yang kita buat dengan nama "iis.txt" tadi, yaitu "Sysocmgr.exe".

Lalu bagaimana instalasinya? Gampang. Masuk ke "command prompt" lalu ketik:
sysocmgr /I:%windir%\inf\sysoc.inf /u:c:\iis.txt
dan ikuti saja prosedurnya.

Keterangan:
Trik ini dilakukan di mesin Windows XP & Windows server 2003 dan seharusnya bisa untuk keluarga NT.
[Components] => parameter untuk menginstall komponen-komponen dalam Windows.
[InternetServer] => parameter untuk merubah default path FTP dan WWW.
iis_htmla = on => "on" menyatakan Kondisi siap melakukan instalasi, yaitu "web based admin tool".

Referensi:
- "Unattended.doc" from the Server CD, "support\tools\deploy.cab\unattend.doc"
- "www.syngress.com"

ava started as a project called "Oak" (The name came from an oak tree that stood outside the Sun Microsystems office) by James Gosling in June 1991 for use in a set top box project.^[3] Gosling's goals were to implement a virtual machine and a language that had a familiar C/C++ style of notation. The first public implementation was Java 1.0 in 1995. It promised "Write Once, Run Anywhere" (WORA), providing no-cost runtimes on popular platforms. It was fairly secure and its security was configurable, allowing network and file access to be restricted. Major web browsers soon incorporated the ability to run secure Java "applets" within web pages. Java became popular quickly. With the advent of "Java 2", new versions had multiple configurations built for different types of platforms. For example, J2EE was for enterprise applications and the greatly stripped down version J2ME was for mobile applications. J2SE was the designation for the Standard Edition. In 2006, new "J2" versions were renamed Java EE, Java ME, and Java SE, respectively.

In 1997, Sun approached the ISO/IEC JTC1 standards body and later the Ecma International to formalize Java, but it soon withdrew from the process.^[4][5][6] Java remains a proprietary de facto standard that is controlled through the Java Community Process.^[7] Sun makes most of its Java implementations available without charge, with revenue being generated by specialized products such as the Java Enterprise System. Sun distinguishes between its Software Development Kit (SDK) and Runtime Environment (JRE) which is a subset of the SDK, the primary distinction being that in the JRE the compiler is not present.

On November 13, 2006, Sun released parts of Java as free/open source software, under the GNU General Public License (GPL). The release of the complete source code under GPL is expected in the first half of 2007.

BASIC

Microsoft staff photo from December 7, 1978. Gates on bottom row, far left.

After reading the January 1975 issue of Popular Electronics that demonstrated the Altair 8800, Gates contacted MITS (Micro Instrumentation and Telemetry Systems), the creators of the new microcomputer, to inform them that he and others were working on a BASIC interpreter for the platform.^[20] In reality, Gates and Allen did not have an Altair and had not written code for it; they merely wanted to gauge MITS's interest. MITS president Ed Roberts agreed to meet them for a demo, and over the course of a few weeks they developed an Altair emulator that ran on a minicomputer, and then the BASIC interpreter. The demonstration, held at MITS's offices in Albuquerque, was a success and resulted in a deal with MITS to distribute the interpreter as Altair BASIC. Paul Allen hired into MITS,^[21] and Gates took a leave of absence from Harvard to work with Allen at MITS, dubbing their partnership "Micro-soft" in November 1975.^[21] Within a year, the hyphen was dropped, and on November 26, 1976, the tradename "Microsoft" was registered with the USPTO.^[21]

Microsoft's BASIC was popular with computer hobbyists, but Gates discovered that a pre-market copy had leaked into the community and was being widely copied and distributed. In February 1976, Gates wrote an Open Letter to Hobbyists in the MITS newsletter saying that MITS could not continue to produce, distribute, and maintain high-quality software without payment.^[22] This letter was unpopular with many computer hobbyists, but Gates persisted in his belief that software developers should be able to demand payment. Microsoft became independent of MITS in late 1976, and it continued to develop programming language software for various systems.

According to Gates, people at Microsoft often did more than one job during the early years; whoever answered the phone when an order came in was responsible for packing and mailing it. Gates oversaw the business details, but continued to write code as well. In the first five years, he personally reviewed every line of code the company shipped, and often rewrote parts of it as he saw fit

Albert Einstein

Albert Einstein (German pronunciation (help·info)) (March 14, 1879 – April 18, 1955) was a German-born theoretical physicist who is widely considered to have been one of the greatest physicists of all time. While best known for the theory of relativity (and specifically mass-energy equivalence, E = mc2), he was awarded the 1921 Nobel Prize in Physics “for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect.”[1]

Einstein's many contributions to physics include his special theory of relativity, which reconciled mechanics with electromagnetism, and his general theory of relativity which extended the principle of relativity to nonuniform motion, creating a new theory of gravitation. His other contributions include relativistic cosmology, capillary action, critical opalescence, classical problems of statistical mechanics and their application to quantum theory, an explanation of the Brownian movement of molecules, atomic transition probabilities, the quantum theory of a monatomic gas, thermal properties of light with low radiation density (which laid the foundation for the photon theory), a theory of radiation including stimulated emission, the conception of a unified field theory, and the geometrization of physics.

Works by Albert Einstein include more than fifty scientific papers but also non-scientific works, including About Zionism: Speeches and Lectures by Professor Albert Einstein. (1930), Why War? (1933, co-authored by Sigmund Freud), The World As I See It (1934), Out of My Later Years (1950), and a book on science for the general reader, The Evolution of Physics (1938, co-authored by Leopold Infeld).[2]

In 1999 Einstein was named Time magazine's "Person of the Century". In popular culture the name "Einstein" has become synonymous with genius.