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RE:ddd
Internetworking functions of the network layer include network addressing and best path selection for traffic
In network addressing, one part of the address is used to identify the path used by the router and the other is used for ports or devices on the network
Routed protocols allow routers to direct user traffic; routing protocols work between routers to maintain path tables
Network discovery for distance-vectoe routing involves exchange of routing tables; problems can include slow convergence
For link-state routing, routers calculate shortest paths to other routers; problems can include inconsistant updates
Balanced hybrid routing uses uses attribs of both link state and distance-vector routing, and can apply paths to several protocols
Path determination for traffic going through a network cloud, occurs at the network layer. The path determination function enables a router to evaluate the available paths to a dest and to est the preffered handling of a packet
Routing services use network topology info when evaluating network paths. This info can be configured by the administer or collected through dynamic process running in the network
The net layer interfaces to networks and provides best-effort end-to-end packet delivery services to its user, the transport layer. The net layer uses the ip routing table to send packets from the source network to the dest network
After the router determines which path to use, it proceeded with forwarding the packet. It takes the packet that it accepted on one interface and forwards it to another interface ot port that reflects the best path to the packet's destination
11.1.3.1. Explain how routers route packets from source to destination.
To be truly practical, a network must consistently represent the paths available between the routyers.
Using these addresses the net layer can provide a relay connection that interconnects independent networks
The consistency of L3 addresses accross the entire network also improves bandwidth by preventing unnecessaruy broadcasts. Broadcasts invoke unnecessary process overheadd and waste capacity on any devices or links that do not need to receive the broadcast...
By using consistent end-to-end addressing to represent the path of media connections, the network layer can find a path to the dest without unneceesarily burdening the devices or links on the internetwork with broadcasts
11.1.4.1. Explain that both networks and individual hosts on a network must have addresses.
The 11.1.5.1. Explain best path selection and packet switching as the two basic processes of a router.
A router generally relays a packet from one data link to another, using two basic functions, a path
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