Sage-Tips

How does the Internet know where to send me?

The routers determine where to send information from one computer to another. Routers are specialized computers that send your messages and those of every other Internet user speeding to their destinations along thousands of pathways.

How is data sent across the internet?

Data travels across the internet in packets. When you send an e-mail to someone, the message breaks up into packets that travel across the network. Different packets from the same message don’t have to follow the same path. That’s part of what makes the Internet so robust and fast.

How messages are sent and received across Internet?

It works by using a packet routing network that follows Internet Protocol (IP) and Transport Control Protocol (TCP) [5]. Data sent over the internet is called a message, but before messages get sent, they’re broken up into tinier parts called packets.

How does a router forward data packets?

A packet is typically forwarded from one router to another router through the networks that constitute an internetwork (e.g. the Internet) until it reaches its destination node. Then, using information in its routing table or routing policy, it directs the packet to the next network on its journey.

How do routers know which device to send packets to?

The router uses network address translation (NAT). Every connection has a source address, a source port, a destination address, and a destination port. When the router is sending the packets to the internet, it changes the source address from a private address to it’s public address.

How does a data packet travel from one router to another?

The data packet is enclosed within a data envelope. That envelope has the destination address and the return address. The router looks at that, and based upon it’s internal information routes that packet to another router that is somewhat closer to the destination. And so on until the packet arrives at the destination address.

How does a router calculate the routing of packets?

Different routing protocols may calculate things in different ways. Basically, when a router sees a packet, it looks up the network for the address in it’s routing table, and forwards it to either the next router closer, or it’s destination host. Cyber espionage is on the rise.

How does a router find the shortest/best path to reach the destination?

Using all these informations router finds the shortest/best path to reach the destination network. By exchanging these network information the router builds up what is called as the routing table. Once the routing table is formed, packet forwarding can be done by the router.

How does the routing table work in a router?

Data from these are collected into a routing table. In high-end implementations, the details of the routing table are downloaded into an ASIC that contains a forwarding table. When a packet arrives, the router extracts the destination address and performs a Longest Prefix Match search on the routing/forwarding table.