IP issues and Multi

[n00bs]

2kcastle said:

I've read lot about ways you can have two or three isp's for the same computer but no-one has said how three computers ended up with the same one.

Most people have this view that the Internet is this homogeneous thing. It is really not, it is a bunch of independent networks connected at so-called peering points. Networks connect using peering agreements where there is often a "terminating cost" for the bandwidth used.

At some point someone realized that many pages on the Internet are fairly static. Instead of getting the same page for every request that is made, you could simply store a copy of the first request on your network and give that copy to other people requesting the page. This is known as a cache server and saves money by cutting the fees you pay for termination at the peering point . The downside is that webservers will typically be slower to respond than on a "better" designed network.

The way it works these days is that your requests are quietly redirected to the cache without you knowing. If the page you are requesting is not in the cache, it will fetch it for you. Since the cache is the one interacting with the webserver, it will be the one showing up in the webserver logs. So, every user that is redirected to that cache will show up as the same ip.

Does that answer your question?

Edit, to clear up one thing: An IP (Internet Protocol) number is an address on the Internet. An ISP (Internet Service Provider) is a company that provides access to the internet. An ISP has a pool of IP numbers that they assign to their users when they are online.

[2kcastle]

I have no idea i was with you right up to fairly static.

[n00bs]

2kcastle said:

I have no idea i was with you right up to fairly static.

So, a concrete example: I want to read the IK rules.

Without a cache server, I type the address into firefox and hit return. Firefox creates a connection to the IK server and requests the webpage containing the rules. The request travels over my home network, onto Comcasts network, then Global Exchange, Eurorings, Hosteurope before hitting the IK server somewhere in Germany. The IK server returns the page along the same path. Since my machine was communicating with the IK server, my IP address will be in the logs.

Depending on the agreements between the networks, each transition from one network to another may involve payment. To save those payments the ISPs install cache servers:

With a cache server and the page in the cache, I type the address into firefox and hit return. Firefox creates a connection but it is intercepted and forwarded to the cache server. The cache server looks up the page in its cache and returns the page.

If the page is not in the cache I type the address into firefox and hit return. Firefox creates a connection but it is intercepted and forwarded to the cache server. Since the cache server does not have the content in its cache it has to go fetch the page from the server. *It* creates a connection to the IK server and requests the webpage containing the rules. The request travels over my home network, onto Comcasts network, then Global Exchange, Eurorings, Hosteurope before hitting the IK server somewhere in Germany. The IK server returns the page along the same path. The cache then stores the data in case someone else requests it, as well as returning the data to the user. Since the cache server interacted with the IK server, its IP address will be in the logs.

This is a little simplified but covers the concepts. Something like a webforum changes often and the pages are user specific so the cache doesn't store them. Every request will go through the cache but get forwarded to the forum server. Since cache servers are shared between many users, all those users will show up as having the same IP address.

[blazed]

i suddenly feel really dumb...

[intchanter]

Don't. n00bs and I didn't come by this knowledge overnight, and those with specialty skills sometimes have trouble translating that knowledge to a form understandable outside that specialty.

Just try to explain some of the more subtle areas of Inselkampf play, and you'll see exactly what I mean. That doesn't mean she's stupid, just that there's an experience gap. And there are usually other experience gaps that run the other direction.

For instance, I /still/ couldn't name five american football teams from memory, I couldn't begin to explain rugby or polo to you, and the one time I sat through an international football/soccer game, I couldn't imagine what would cause someone to watch when a 3-point tie is a high-scoring game.

I'm okay with that particular gap, and there are many I associate with who don't care what happens inside a computer as long as it works. And it takes all of us to make this world work.

[n00bs]

blazed said:

i suddenly feel really dumb...

You shouldn't. As Intchanter points out, I have been doing this for a while. I started programming in the 70s, had access to my first networked computer in 82, got on the Internet in 88, installed the very first webbrowser the day it was released in '93, wrote my first webbased game in '94, worked for an ISP (that some of you, judging by your nationalities, love to hate) for 4 years doing network planning and service implementation. These days I am living in the US where I work as a software developer.

With 30 years of software development experience and 25 years of networking it is not strange that a few items rubbed off. I am actually a little embarrassed that Intchanter thought of proxies before I did. My only excuse is that it was early in the morning here...

I am pretty sure there are areas where you know much more than I do, this question just happened to be in an area where I know more than you.