Pemrograman Jaringan Routing Concept Aurelio Rahmadian Objektif Pengenalan

Pemrograman Jaringan Routing Concept Aurelio Rahmadian

Objektif �Pengenalan �Router = Komputer �WAN Protocol �Bagian-bagian Router �Dokumentasi Perancangan �Konsep Routing �Static Routing �Dynamic Routing �Prinsip Routing Table

Pengenalan �Router merupakan perangkat yang berada di tengah jaringan �Secara sederhana, dapat dikatakan bahwa router menghubungkan satu jaringan dengan lainnya �Router bertanggung jawab untuk pengiriman packet melalui jaringan yang berbeda

Pengenalan �Saat ini router juga ditambahkan pada satelit di luar angkasa. Router ini mampu menjalurkan traffic IP antara satelit-satelit yang ada dengan cara yang sama seperti packet yang bergerak di bumi sehingga dapat mengurangi delay dan memberikan fleksibilitas yang lebih baik

Pengenalan �Tanggung jawab utamanya adalah meneruskan (forwarding) packet dari satu jaringan ke jaringan lain �Hal ini dimungkinkan karena kemampuan router untuk menjalurkan packet antar jaringan sehingga divais yang berada pada jaringan yang berbeda dapat saling berkomunikasi

Router = Komputer �Router memiliki banyak komponen hardware dan software yang juga ditemui di perangkat komputer lain, mencakup: ◦ ◦ CPU RAM ROM Operating System

Router = Komputer � Router menghubungkan beberapa jaringan, artinya router memiliki beberapa interface yang masing-masing merupakan bagian dari jaringan yang berbeda � Ketika menerima packet IP pada salah satu interface, router menentukan interface mana yang akan digunakan untuk meneruskan packet tersebut agar sampai ke tempat tujuan. Interface yang digunakan untuk meneruskan dapat berupa: ◦ the network of the final destination of the packet (the network with the destination IP address of this packet) - LAN ◦ network connected to another router that is used to reach the destination network - WAN

Router = Komputer �Tanggung jawab utama router adalah meneruskan packet ke tujuannya, dengan cara: ◦ Menentukan jalur terbaik untuk mengirim packet ◦ Meneruskan packet ke tujuan

Router = Komputer �Router menggunakan routing table yang dimiliki untuk menentukan jalur terbaik �Saat menerima packet, router memeriksa destination IP address dari packet tersebut dan mencocokkan alamat tersebut dengan routing table �Routing table mencakup interface yang digunakan untuk meneruskan packet

Router = Komputer �Sangat memungkinkan bahwa suatu router akan menerima packet yang dienkapsulasi dengan suatu jenis data link fram, seperti Ethernet, tetapi kemudian meneruskan packet tersebut dengan jenis enkapsulasi data link frame yang berbeda, misalnya Point-to-Point Protocol (PPP) �Enkapsulasi data link tergantung pada jenis interface pada router dan jenis media yang terhubung dengannya

DTE DCE

WAN Protocol �High-Level Data Link Control (HDLC) �Point-to-Point Protocol (PPP) �Frame Relay

Bagian-bagian Router Power Supply WIC Shield NVRAM CPU SDRAM Fan

Bagian-bagian Router High Speed WIC (HWIC) Console Port USB Port Flash Memory Fast Ethernet Port Auxiliary Port Power Cable Connector

Bagian-bagian Router � CPU The CPU executes operating system instructions, such as system initialization, routing functions, and switching functions. � RAM stores the instructions and data needed to be executed by the CPU. RAM is used to store these components: ◦ Operating System: The Cisco IOS (Internetwork Operating System) is copied into RAM during bootup. ◦ Running Configuration File: This is the configuration file that stores the configuration commands that the router IOS is currently using. With few exceptions, all commands configured on the router are stored in the running configuration file, known as running-config. ◦ IP Routing Table: This file stores information about directly connected and remote networks. It is used to determine the best path to forward the packet. ◦ ARP Cache: This cache contains the IPv 4 address to MAC address mappings, similar to the ARP cache on a PC. The ARP cache is used on routers that have LAN interfaces such as Ethernet interfaces. ◦ Packet Buffer: Packets are temporarily stored in a buffer when received on an interface or before they exit an interface.

Bagian-bagian Router �RAM is volatile memory and loses its content when the router is powered down or restarted.

Bagian-bagian Router � ROM is a form of permanent storage. Cisco devices use ROM to store: ◦ The bootstrap instructions ◦ Basic diagnostic software ◦ Scaled-down version of IOS � Flash Memory Flash memory is nonvolatile computer memory that can be electrically stored and erased. Flash is used as permanent storage for the operating system, Cisco IOS. In most models of Cisco routers, the IOS is permanently stored in flash memory and copied into RAM during the bootup process, where it is then executed by the CPU.

Bagian-bagian Router �NVRAM (Nonvolatile RAM) does not lose its information when power is turned off. This is in contrast to the most common forms of RAM, such as DRAM, that requires continual power to maintain its information. NVRAM is used by the Cisco IOS as permanent storage for the startup configuration file (startupconfig). �ROM, flash memory, and NVRAM does not lose its contents when the router loses power or is restarted.

Dokumentasi Perancangan

Dokumentasi Perancangan �When configuring a router, certain basic tasks are performed including: ◦ ◦ ◦ Naming the router Setting passwords Configuring interfaces Configuring a banner Saving changes on a router Verifying basic configuration and router operations

Konsep Routing �Remote networks ditambahkan pada routing table dengan konfigurasi static route atau menggunakan dynamic routing protocol �Ketika OS mengetahui adanya sebuah remote network dan interface yang akan digunakan untuk mencapai jaringan tersebut, jalur tersebut akan ditambahkan ke routing table selama interface tersebut aktif

Static Routing �Static route mencakup network address dan subnet mask dari remote network, diikuti dengan IP address dari next-hop router atau exit interface �Static route ditandai dengan kode ‘S’ pada routing table

Static Routing �Keuntungannya: ◦ Meringankan kerja prosesor yang ada pada router ◦ Tidak ada bandwidth yang digunakan untuk pertukaran informasi routing table antar router ◦ Tingkat keamanan lebih tinggi vs mekanisme lainnya �Kekurangannya: ◦ Admin harus mengetahui informasi tiap-tiap router yang terhubung jaringan ◦ Jika terdapat penambahan/perubahan topologi jaringan, admin harus mengubah isi routing table ◦ Tidak cocok untuk jaringan yang besar

Static Routing Saat-saat untuk menggunakan static routing: � A network consists of only a few routers. Using a dynamic routing protocol in such a case does not present any substantial benefit. On the contrary, dynamic routing may add more administrative overhead. � A network is connected to the Internet only through a single ISP. There is no need to use a dynamic routing protocol across this link because the ISP represents the only exit point to the Internet. � A large network is configured in a hub-and-spoke topology. A hub-and-spoke topology consists of a central location (the hub) and multiple branch locations (spokes), with each spoke having only one connection to the hub. Using dynamic routing would be unnecessary because each branch has only one path to a given destination-through the central location.

Dynamic Routing �Dynamic routing protocols digunakan router untuk membagi informasi tentang jaringan yang dapat dijangkau. Routing protocol melakukan beberapa aktifitas mencakup: ◦ Network discovery ◦ Updating and maintaining routing tables

Dynamic Routing �Kategori algoritma routing: ◦ Distance vector ◦ Link state

Dynamic Routing �Distance Vector ◦ Routing information is only exchanged between directly connected neighbors ◦ This means a router knows from which neighbor a route was learned, but it does not know where that neighbor learned the route; a router can't see beyond its own neighbors ◦ This aspect of distance vector routing is sometimes referred to as "routing by rumor. “ ◦ Also known as Bellman-Ford algorithm

Dynamic Routing �Link State ◦ Requires that all routers know about the paths reachable by all other routers in the network ◦ Link-state information is flooded throughout the link-state domain to ensure all routers posses a synchronized copy of the area's link -state database ◦ From this common database, each router constructs its own relative shortest-path tree, with itself as the root, for all known routes ◦ Also known as Dijkstra’s algorithm

Dynamic Routing

Dynamic Routing �Distance Vector

Dynamic Routing �Link State

Dynamic Routing �Link State

Dynamic Routing �Ada beberapa routing protocol yang tersedia. Berikut adalah beberapa routing protocol yang umum digunakan untuk menjalurkan packet IP: ◦ RIP (Routing Information Protocol) ◦ IGRP (Interior Gateway Routing Protocol) ◦ EIGRP (Enhanced Interior Gateway Routing Protocol) ◦ OSPF (Open Shortest Path First) ◦ IS-IS (Intermediate System-to-Intermediate System) ◦ BGP (Border Gateway Protocol)

Dynamic Routing

Dynamic Routing �Routing protocol interior didesain untuk jaringan yang dikontrol oleh suatu organisasi. Kriteria disain untuk routing protocol interior untuk mencari jalur terbaik pada jaringan �Routing protocol eksterior didesain untuk penggunaan antara dua jaringan yang berbeda yang dikontrol oleh dua organisasi yang berbeda. Umumnya digunakan antara ISP dengan ISP atau antara ISP dengan perusahaan

Prinsip Routing Table �Every router makes its decision alone, based on the information it has in its own routing table. �The fact that one router has certain information in its routing table does not mean that other routers have the same information. �Routing information about a path from one network to another does not provide routing information about the reverse, or return, path.