Definition of Router

sumber:https://fikriawanschool.blogspot.com/2016/08/pengertian-router-dan-konfigurasi-router.html

Definition of Router

Router is a network computer that is in charge or functioned to connect two or more networks and is responsible for carrying data through a set of networks by choosing the best path for data to pass. And another thing the router should know is how many ports it has and what types. This information is usually recognized automatically by the router’s operating system, and requires no configuration. To identify the ports through which the router passes, the port type is usually shortened to two letters or numbers that identify the port order between ports of the same type. After the router knows all the port information connected to it, the router will connect it to form entries in a table, this table is in the router’s memory and is usually called a routing table. All information in the routing table states that there is a connection between routers, so this is what sends data safely to its destination. The entire routing process will be explained in this discussion.

ROUTING Routing Basics

Routing is used for the process of taking a packet from a device and sending it through the network to another device on a different network. If your network does not have a router, then obviously you are not routing. To be able to do packet routing, there are things that must be known:

• Destination address

• Neighboring routers from which a router can learn about remote networks

• Possible routes to all remote networks

• The best route for each remote network The router maintains a routing table that describes how to find remote networks The types of routing are:

• Routing statis
• Routing default
• Routing dinamis

1. Routing Statis

Static routing occurs if Admin manually adds routes in routing table of each router. Static routing has the following advantages:

• No overhead (processing time) on router CPU (routers are cheaper than dynamic routers)

• No bandwidth is used between routers.

• Static routing adds security, because administrators can choose to specify access routing to only certain networks.

Static routing has the following disadvantages:

• The administration must fully understand the internetwork and how each router is connected in order to properly configure the router.

• If a network is added to the internetwork, the Administration must add a route to all routers—manually

• Static routing is not suitable for large networks because maintaining it would be a full-time job in itself. The use of the Default gateway and static routes mentioned above can be considered according to our needs when designing a network, whether the route that is made is rather complex or simple. For simple route design, it is possible to use the default gateway. However, if the network conditions are too complex, we can use static routing or both in combination, namely using the default gateway and static routes at certain points.

Pay attention to the following network conditions From the network design above we can see how to configure the Default gateway and when a static route is needed. Later it will be explained further how to configure the default gateway and static route on the router which in this case we use a PC Router. The routing table consists of route entries and each route entry consists of an IP address, a sign to indicate direct or indirect routing, router addresses and interface numbers, see the routing table below:

Explanation of the routing table above:
q 0.0.0.0 menunjukkan router default, alamat 172.16.7.21
q 127.0.0.0 Jaringan Loopback. Tiap datagram yang yang dikirim ke 127.0.0.0 akan dirutekan ke 127.0.0.1 dan direfleksikan balik.
q 172.16.0.0 Alamat jaringan. Datagram yang ditujukan ke jaringan ini akan dirutekan melalui adapter 172.16.7.21.
q 172.16.7.21 Alamat Network Adapter Host. Perhatikan datagram yang dikirimkan ke alamat ini akan dirutekan kembali ke Loopback.
q 172.16.255.255 Alamat Broadcast untuk jaringan 172.16.0.0. Broadcast akan dirutekan ke jaringan melalui adapter 172.16.7.21. Entri akan seperti ini harus ditambahkan bila pesan broadcast akan dirutekan ke jaringan remote.
q 224.0.0.0 Alamat multicast yang digunakan secara internal oleh windows.
q 255.255.255.255 Alamat Broadcast local (router tidak meneruskan broadcast ke jaringan lain).

2. Routing DefaultRouting default

   used to send packets manually adding a router to a remote destination network that is not in the routing table, to the next hop router. Usually used on networks that have only one exit.

3. Routing DinamisRouting

   dynamic is when the routing protocol is used to find the network and update the routing table on the router. And it’s easier than using static and default routing, but it will set you apart in terms of processes on the router’s CPU and bandwidth usage of network links.

Routing and Routing Protocol Protocol is nothing but a formal description of the set or rules and conversions that determine how devices on a network exchange information. The following are the two basic types of protocols. · Routed protocols are protocols that can be routed by a router. protocol allows routers to correctly interpret logical networks. Examples of routed protocols: IP, IPX, AppleTalk, and DECnet. · Routing protocols These protocols are used to maintain the routing table on routers. Examples of routing protocols include OSPF, RIP, BGP, IGRP, and EIGRP.

(RIP)Routing Information Protocol. Distance vector protocol – maintains a list of distances to other networks based on the number of hops, i.e. the number of routers that packets must pass through to reach the destination address. RIP is limited to 15hops only. Broadcasts are updated every 30 seconds for all RIP routers to maintain integrity. RIP is suitable to be implemented for small networks.

(OSPF) Open Shortest Path First. Link state protocol—menggunakan kecepatan jaringan berdasarkan metric untuk menetapkan path-path ke jaringan lainnya. Setiap router merawat map sederhana dari keseluruhan jaringan. Update-update dilakukan via multicast, dan dikirim.Jika terjadi perubahan konfigurasi.OSPF cocok untuk jaringan besar.

(EIGRP) Enhanced Interior Gateway Routing Protocol. Distance vector protocol—merawat satu set metric yang kompleks untuk jarak tempuh ke jaringan lainnya. EIGRP menggabungkan juga konsep link state protocol.Broadcast-broadcast di-update setiap 90 detik ke semua EIGRP router berdekatan. Setiap update hanya memasukkan perubahan jaringan. EIGRP sangat cocok untuk jaringan besar.

(BGP) Merupakan distance vector exterior gateway protocol yang bekerja secara cerdas untuk merawat path-path ke jaringan lainnya. Up date-update dikirim melalui koneksi TCP.

Distance Administration Administrative distance (abbreviated AD) is used to measure the so-called trustworthiness of routing information received by a router from a neighboring router. AD is an integer 0 – 255, where 0 is the most reliable and 255 means no data traffic will go through this route. If both routers receive two updates regarding the same remote network, then the first thing the router checks is AD. If one of the advertised routes (announced by another router) has a lower AD than the others, the route with the lowest AD will be placed in the routing table. If both advertised routes have the same AD, the so-called routing protocol metric (eg number of hops or bandwidth of the connection) will be used to find the best path to the remote network. If both AD and metric are the same, load-balance is used. The following table shows the default AD used by a Cisco router to decide which route to take to a remote network.