BASICS OF NETWORK ROUTING

We can find the core network routing some router configuration, router work, simulations of static routes and routing table. Routing is the process of defining routes for the packets to their destination across an international network and this is done by the router. 

Routing consists of two separate tasks.

1. Define paths and packages through the network. 

2. Forwarding data packets based on predefined routes. 

Generally, two types of routing. 

Static and dynamic routing 

Routing can be done manually define roads or paths for packets to reach their destination. This is called static routing. 

Indication routing works well for small networks when using static routing, the routing table for each router must be updated whenever there is any change in network configuration or topology. A router whose routing table is not updated regularly, can not communicate with other routers. 

But on the other end in most networks, routing is done using dynamic routing. In dynamic routing, routing protocols like RIP, OSPF, etc. to create and maintain routing tables at each router. In practice, dynamic routing works well, the static routing 

Routing Table 

A routing table is a set of rules from a tabular format, which is used to define routes data packets. All network devices that have IP-based networking functionality such as routers and switches use routing tables. Routing table stores information and settings for each router on the IP network enabled. A routing table contains the information required to send packages to their destination. 

When you receive a packet network devices match the information contained in packets and information in the routing tables and then define the shortest possible route for transmission of packets to their destination. 

Each packet contains information about its origin and destination and routing table contains the following information. 

• Destination: IP address of final destination of the packet (next hop). Next hop: The IP address that the package is sent 

• Metrics: allocate costs for each route, so that more effective methods can be collected. 

• Tracks: Includes directly attached subnet, direct, indirect subnets not directly connected to the device, but can be accessed via one or more links 

• Interface: network interface device output will be used to send the package to its final destination.

Routing tables can be maintained manually by the network administrator or dynamically (automatically). Static tables of the network remains unchanged, unless the administrator changes the network. Routing tables can be maintained manually or dynamically. Tables for static network devices do not change unless a network administrator manually changes. In dynamic routing with network devices like routers and switches routing tables with dynamic routing protocols like RIP, OSPF, etc. In dynamic routing, network devices, listening devices and detect or network failure and congestion of packets. 

Routing on the Internet 

Routing is the method by which data is its destiny from one computer to another. On the Internet there are 3 main points of the route. 

1. Physical Address Search 
   2. Determination of the network between gateways 
   3. Numeric and symbolic Directions 
   
   
2. Find the physical address is the Internet routing method and is used when sending a datagram computer. It is necessary to encapsulate IP datagram’s. This encapsulation requires that the local network or physical address. 
   
   
3. If a team wants to send IP datagram’s that need to embed the physical address of the destination network device in the frame. This address can be obtained using the table that will map the IP address with the physical address. This table can be configured in a file that can be read into memory at startup. Equipment that normally uses Address Resolution Protocol (ARP), which acts dynamically to maintain the translation table. 
   
   
4. The second method is necessary because the Internet consists of a large number of local networks interconnected by gateways. These gateways are known as routers that have both physical and logical connection to various networks. 
   Determining the best fit and the gateway port to a specific IP address is called routing. 
   
   
5. The third method usually involves the translation of human amicably (names) to the numerical address (IP address). IP address can not be remembered for its numerical form, but the simplest names (domain names) is easy to remember, for example, www.yahoo.com, www.google.com, www.msn.com are easier to remember than IP -- addresses 122.11.22.34, 223.45.66.76, 155.44.55.120. DNS translates domain names into IP address and IP address of the domain name. Domain translation of intellectual property is a need for communication on the Internet because Internet communication is done through IP addresses. 
   
   
6. The communication between routers.
   
   
7. The Internet is a network of networks. The Internet is composed of a large number of independent systems, each of which also consists of routing domains. These autonomous systems are usually large companies or universities. Within the autonomous system, a router communicates with the router via the domain of the best in routing protocols, known as interior gateway protocols. The autonomous system is connected through gateways, such as exchange of information between domains using routing protocol, also called exterior gateway protocols. 
   
   
8. Or RIP (Routing Information Protocol) is the most common protocol and Interior Gateway Protocol such as the recently open shortest path first (OSPF). The purpose of these protocols is that routers to exchange locally for all routers in the AS must have a consistent and timely information. 
   
   
9. When a host receives information from the new route is likely that the update is not only her but also sends this new and updated information for all hosts are connected so they can update themselves. Therefore, these changes are

            propagated throughout the network.