Routing: 1. Routing Default 2. Routing Statis 3. Routing Dinamis Algoritma Routing (Dinamis) : 1. Distance Vector Routing 2. Link State Routing
Distance Vector Routing Protocols Contoh Protokol Routing Distance Vector : Routing Information Protocol (RIP) Interior Gateway Routing Protocol (IGRP) Enhanced Interior Gateway Routing Protocol (EIGRP)
Distance Vector Routing Protocols Distance Vector Technology The Meaning of Distance Vector: A router using distance vector routing protocols knows 2 things: Distance to final destination Vector, or direction, traffic should be directed
Distance Vector Routing Protocols Karakteristik Distance Vector : Update Periodik Tetangga Update Broadcast Seluruh tabel Routing dimasukkan saat update
Distance Vector Routing Protocols Routing Protocol Algorithm: (Algoritma adalah Sebuah prosedur untuk memenuhi sebuah kerja tertentu) Tujuan Algoritma Routing: 1. Mengirim dan menerima Update 2. Mengkalkulasi Jalur terbaik 3. Mendeteksi dan bereaksi terhadap perubahan topologi
Distance Vector Routing Protocols Routing Protocol Characteristics Kriteria yang digunakan untuk membandingkan protokol routing : -Waktu konvergensi -Skalabilitas -Penggunaan Resources -Implementasi dan maintenance
Distance Vector Routing Protocols
Network Discovery Router initial start up (Cold Starts) -Initial network discovery Network yang terhubung langsung ditempatkan di tabel routing.
Network Discovery Tukar Menukar tabel informasi pertama kali Jika sebuah protokol routing di konfigurasi, maka akan terjadi saling tukar informasi routing Update Routing diterima dari router lainnya -Router melakukan memeriksa informasi update jika ada informasi baru -Jika ada informasi baru: -Metric di update -Informasi baru disimpan ke dalam tabel routing
Network Discovery Tukar Menukar Informasi Routing Konvergensi router tercapai apabila - Seluruh tabel routing pada network tersebut berisi informasi network yang sama. Jika belum tercapai, Router akan terus saling bertukar informasi routing -Jika tak ada informasi baru ditemukan maka Convergence (konvergensi ) telah reached (tercapai)
Network Discovery Konvergensi harus dicapai sebelum sebuah network dianggap beroperasi lengkap Kecepatan pencapaian konvergensi tergantung dari dua kategori yang saling berhubungan - Kecepatan broadcast informasi routing - Kecepatan dalam mengkalkulasi route
Permasalahan pada Distance Vector Konvergensi yang Lambat Skalabilitas yang terbatas Routing Loops
Inconsistent Routing Entries Each node maintains the distance from itself to each possible destination network.
Inconsistent Routing Entries (Cont.) Slow convergence produces inconsistent routing.
Inconsistent Routing Entries (Cont.) Router C concludes that the best path to network 10.4.0.0 is through router B.
Inconsistent Routing Entries (Cont.) Router A updates its table to reflect the new but erroneous hop count.
Count to Infinity Hop count for network 10.4.0.0 counts to infinity.
Defining a Maximum Define a limit on the number of hops to prevent infinite loops.
Routing Loops Packets for network 10.4.0.0 bounce (loop) between routers B and C.
Routing loops adalah kondisi ketika paket dikirimkan secara terus menerus tanpa mencapai tujuannya. Routing Loops
Routing Loops Routing loops may be caused by: -Incorrectly configured static routes -Incorrectly configured route redistribution -Slow convergence -Incorrectly configured discard routes Routing loops can create the following issues -Excess use of bandwidth -CPU resources may be strained -Network convergence is degraded -Routing updates may be lost or not processed in a timely manner
Mengatasi Routing Loops Split Horizon Route Poisoning Hold down timer Trigger Update
Split Horizon It is never useful to send information about a route back in the direction from which the original information came.
Route Poisoning Routers advertise the distance of routes that have gone down to infinity.
Poison Reverse Poison reverse overrides split horizon.
Holddown Timers The router keeps an entry for the network s possible down state, allowing time for other routers to recompute for this topology change.
Triggered Updates The router sends updates when a change in its routing table occurs.
Routing Protocols Today Factors used to determine whether to use RIP or EIGRP include -Network size -Compatibility between models of routers -Administrative knowledge