Sometimes when you are downloading from a filesharing site you may get thwarted with an annoying message saying something like “Your IP chaned, You must have static IP”. What is going on? Even those with dynamic IPs will know that they do not change suddenly in mid-web-surf, and in fact this message is just as commonly seen by people with static IPs. So what gives?
Assuming that the file sharing site is not completely broken, then there is only one sensible explanation for the problem. Your ISP is using a proxy server. At the last moment when you are about to download, the ISP switches the request to go through a proxy server with a different IP. The web server at the file sharing site sees the change in IP and decides not to play along. Why would that be a problem for them, and why does the ISP use the proxy?
There are in fact lots of reasons for the ISP to use a proxy. In the old days they were used to cache commonly accessed static content to speed up web surfing, but those days are gone. There is too much content for it to be practical, and too much risk of caching illegal content.
These days there are two main reasons why the ISPs use proxies in the UK. One is because they have to block content deemed illegal by the IWF. If a URL is designated to be censored, the ISP does it by passing all content on the same IP number through a proxie so they can read the headers and block the specific requests.
You may recall how this had nasty side effects when they suddenly decided an image on Wikipedia was illegal. The result was that wikipedia saw the proxies IP and would not let anyone in the UK do Wikipedia edits. The solution in that case was simple. To save themselves further ridicule the IWF quickly decided that the image was not illegal afterall.
However, it is not likely that this is why downloading is failing on filesharing sites, especially since there is another reason why the ISP will use proxies that fits the circumstances better. Network capacity in the UK is severely limited and ISPs dont want to invest anymore in the infrastructure. instead they want to limit our ability to download too much data by putting caps in their terms and conditions. If you download too much in a month you may be put on a slow network, or even be made to pay extra. But that is not enough for the ISPs whose imagination is not as limited as their bandwidth, and it also leads to people going elsewhere when they get blocked. So in addition that choke the bandwidth for P2P transactions and for websites where people download large files. This means that download speeds are slowed down enough to prevent most users being able to hit their caps, but not so much that everybody notices they are being affected.
So that is what the message means. Your ISP is slowing your downloads by passing it through a slow proxie server. The filesharing site in turn recognises this as a bottleneck and does not accept the download. Your only way out is to choose an ISP like www.bethere.co.uk who does not do this kind of nasty thing. That is what I have just done and no regrets.
