How does the Bouncy Thing Know??!!

[Foxie3a]

I was thinking..

How does my packet of information know where to go?

Ok, so it goes to the IP you say, but how does it know where that IP is physically located, does it try everyone's house before it gets to my ISP? lol

Just set me straight here.

[coin]

every public IP is a unique address (bit ilke your house address) Every router the packet goes though carries a huge address book listing in which direction groups of IP ranges lie (most routers have several in/out points) Your packet simply tells the router where it needs to go and the router points it down the most efficient line to reach that address.


Hope that answers your query:D

[su root]

and, since it's a large internet, if the router doesn't know how to get there, then it passes it on to another router, who checks their records. Eventually one of them will know.

Also, each and every IP in the world is not listed in each and every router, just "groups" of IPs, called "Networks".. When I send a packet to you, the routers are really trying to relay it to your ISP. Your ISP's routers will know more information about their network, and be able to route it to you from there.

[lanman31337]

Routers have tables that know where other routers are. Routers use the shortest distance to the end node, whether it be a printer, a pc, another router. If a router goes down, it rebuilds the router table to know where everything is at that time.

[Foxie3a]

What if it is a newly used IP.

then wouldn't it take a long for it to find a router that knows?

[su root]

Routers only route between networks. When the router recieves a packet, it checks where the destination is, and looks at it's routing table.

Routers can operate in two modes: Static or Dynamic. Static is when the configuration is put in manually, and nothing changes. Dynamic is when it figures out what networks it is connected to, and trades routing tables with other routers about what they're connected to.

A new IP will be part of a network, and that network will have to have routers that chat with other routers, so eventually, quite a few routers will know about it.

So the packet will be tossed about on the internet until it expires or a router recognizes it, and knows where to send it.

Chances are that most major backbones will know most of the places in the world already. If not, they will pass it up to an even more major backbone (Canada-wide or US-wide) that would know where it is, failing that, it would be handed up to an international carrier, who would know.