What is a router?

The internet is comprised of a large network of routers. A router makes it possible for different networks of computers to communicate with each other. Each device on the router has a unique MAC(Media Access Controller) Address that is unique for that particular device. If one wanted to see the history of the device, you could track it by its MAC address. Also an IP Address, is given to each device connected to the router. These addresses can be local or global. Most routers will give the devices a local IP address which allows the devices on the network to communicate with each other. These IP addresses are not unique to the device, but they are unique amongst the devices attached to that specific router.

The information on the internet is sent through "packets". These packets are broken down pieces of information that a user is requesting or sending. Routers use the most logical way to send packets, which may not be the most direct way. Each time a packet is sent to a different location that is called a "hop". A "hop" is when the packet lands on different servers. If a person were to send a large amount of packets to a router, then it could cause it to overload. Firewalls are used to prevent this happening.

This is a very broad overview of what this podcast was about, and what I took away from it.


Notes:
The internet is a massive network of computers connected through routers. Without routers this would not be possible. Routers allow transfer of information through different layers. There are 7 layers to the internet, only talking about first 3.

1. Bit Layer - physical data of communication i.e. pins, voltage, one device
2. Communication between devices - using LAN, router is unnecessary (switch)
3. Router -> controls information from LAN to internet.

Internet is sent through packets, these tells where its going and what piece it is. May find path to send traffic through the longer route rather than the direct route.

Protocols - languages routers use to speak to each other.

Routing table - set of rules to send packets over the internet. They are dynamic, constantly changing so the most efficient route is taken.

Router - is sent through "hops" certain protocols have limited number of hops, this information is sent through the data packets.

IP Address - own unique address, so that when you send you can have an address.

MAC Address (Media Access Control) - unique address for every device, different from ip address as its for the device not internet

Network Address Translation - more devices in the world, then we have ip address to connect to the internet. Dynamic IP addresses vs. Static. Local IP address (ones that are assigned through router 192.168.0.1) vs. global address.

Can overload a router, by sending large amounts of packets to it. These are called Service Attacks. Firewalls can prevent service attacks through routers (hardware) or software.

Reference: http://podcasts.howstuffworks.com/hsw/podcasts/techstuff/2011-08-08-techstuff-routers.mp3?_kip_ipx=421756093-1314244694