How a Router Works Last Updated: 2nd Jul 2012 Published: August 2011 A router is a network device found at layer 3 of the OSI model that uses advanced metrics to establish the shortest and fastest link between two network nodes on the internet. A router is responsible for establishing a logical link between your home and a server, for instance at Facebook.
Each interface on a router attaches to a network and the router is responsible for establishing communication between the networks. To find networks that are not directly attached to the router, the router discovers (searches) for other online routers, also referred to as neighbors, and they exchange their routing data. For this to occur, both routers must be running routing protocols.
When a router discovers a neighboring router, both exchange their routing tables filled with paths to networks that each router knows of. The routers then run metrics on the new data to establish the best path (router) to use in order to communicate with a network that is not directly attached.
The metrics run depend on the routing protocols used such as Border Gateway Protocol (BGP), which is the main routing protocol on the internet. Other routing protocols include Open Short Path First (OSPF), Intermediate System to Intermediate System (IS-IS), Enhanced Interior Gateway Routing Protocol (EIGRP) and Routing Information Protocol (RIP).
Most home routers only need to know of the route to the ISP and ISP routers are responsible for knowing links to all networks on the Internet.
Components of a RouterIn most routers, one is bound to find:-
Auxiliary (Aux) port: Used to establish a dialup link to the router from a modem. Aux ports are used for configuration purposes.
Console port: Creates a link between the router and PC and used to send configurations to the router through a terminal on the PC.
Fast Ethernet (FE) ports: These ports use standard Ethernet cables to connect Ethernet devices such a PC or Ethernet switches to the router. Most Ethernet ports on a router will be used to connect to a LAN or VLAN segment.
Switch ports: In routers with inbuilt switches, they will provide ports that are used to connect directly to Ethernet devices. This eliminates need for additional Ethernet switches.
WAN Interface cards: As the name suggests these are used to connect the router to a wide area network. They use technologies such as optic fiber, DSL, or T1.
Logical components: These include the operating system usually referred to as Internetwork Operating System (IOS), routing protocols such as BGP, IS-IS and OSPF, and security protocols such as VPNs or IPS.
Posted in Computers & Consumer Electronics
Each interface on a router attaches to a network and the router is responsible for establishing communication between the networks. To find networks that are not directly attached to the router, the router discovers (searches) for other online routers, also referred to as neighbors, and they exchange their routing data. For this to occur, both routers must be running routing protocols.
When a router discovers a neighboring router, both exchange their routing tables filled with paths to networks that each router knows of. The routers then run metrics on the new data to establish the best path (router) to use in order to communicate with a network that is not directly attached.
The metrics run depend on the routing protocols used such as Border Gateway Protocol (BGP), which is the main routing protocol on the internet. Other routing protocols include Open Short Path First (OSPF), Intermediate System to Intermediate System (IS-IS), Enhanced Interior Gateway Routing Protocol (EIGRP) and Routing Information Protocol (RIP).
Most home routers only need to know of the route to the ISP and ISP routers are responsible for knowing links to all networks on the Internet.
Components of a RouterIn most routers, one is bound to find:-
Auxiliary (Aux) port: Used to establish a dialup link to the router from a modem. Aux ports are used for configuration purposes.
Console port: Creates a link between the router and PC and used to send configurations to the router through a terminal on the PC.
Fast Ethernet (FE) ports: These ports use standard Ethernet cables to connect Ethernet devices such a PC or Ethernet switches to the router. Most Ethernet ports on a router will be used to connect to a LAN or VLAN segment.
Switch ports: In routers with inbuilt switches, they will provide ports that are used to connect directly to Ethernet devices. This eliminates need for additional Ethernet switches.
WAN Interface cards: As the name suggests these are used to connect the router to a wide area network. They use technologies such as optic fiber, DSL, or T1.
Logical components: These include the operating system usually referred to as Internetwork Operating System (IOS), routing protocols such as BGP, IS-IS and OSPF, and security protocols such as VPNs or IPS.
Posted in Computers & Consumer Electronics