Pemrograman Jaringan Routing -Aurelio Rahmadian- Objektif Pengenalan Router = Komputer WAN Protocol Bagian-bagian Router Dokumentasi Perancangan Static Routing Dynamic Routing Prinsip Routing Table Pengenalan At the center of the network is the router. Stated simply, a router connects one network to another network. Therefore, the router is responsible for the delivery of packets across different networks. Pengenalan Routers are now being added to satellites in space. These routers will have the ability to route IP traffic between satellites in space in much the same way that packets are moved on Earth, thereby reducing delays and offering greater networking flexibility. Pengenalan Its primary responsibility of forwarding packets from one network to the next. It is only because of the router's ability to route packets between networks that devices on different networks can communicate. Router = Komputer Routers have many of the same hardware and software components that are found in other computers including: CPU RAM ROM Operating System Router = Komputer A router connects multiple networks. This means that it has multiple interfaces that each belong to a different IP network. When a router receives an IP packet on one interface, it determines which interface to use to forward the packet onto its destination. The interface that the router uses to forward the packet may be: ◦ 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 The primary responsibility of a router is to direct packets destined for local and remote networks by: ◦ Determining the best path to send packets ◦ Forwarding packets toward their destination Router = Komputer The router uses its routing table to determine the best path to forward the packet. When the router receives a packet, it examines its destination IP address and searches for the best match with a network address in the router's routing table. The routing table also includes the interface to be used to forward the packet. Router = Komputer It is very likely that a router will receive a packet that is encapsulated in one type of data link frame, such as an Ethernet frame and when forwarding the packet, the router will encapsulate it in a different type of data link frame, such as Point-toPoint Protocol (PPP). The data link encapsulation depends on the type of interface on the router and the type of medium it connects to. DTE DCE WAN Protocol High-Level Data Link Control (HDLC) Point-to-Point Protocol (PPP) Frame Relay Bagian-bagian Router Power Supply WIC Shield 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 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 IPv4 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 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 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 (startup-config). 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 Static Routing Remote networks are added to the routing table either by configuring static routes or enabling a dynamic routing protocol. When the IOS learns about a remote network and the interface that it will use to reach that network, it adds that route to the routing table as long as the exit interface is enabled. A static route includes the network address and subnet mask of the remote network, along with the IP address of the next-hop router or exit interface. Static routes are denoted with the code S in the routing table. 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 are used by routers to share information about the reachability and status of remote networks. Dynamic routing protocols perform several activities, including: Network discovery Updating and maintaining routing tables Dynamic Routing There are several dynamic routing protocols for IP. Here are some of the more common dynamic routing protocols for routing IP packets: ◦ 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) Prinsip Routing Table 1. Every router makes its decision alone, based on the information it has in its own routing table. 2. The fact that one router has certain information in its routing table does not mean that other routers have the same information. 3. Routing information about a path from one network to another does not provide routing information about the reverse, or return, path.