wget: Downloading from different IP addresses does not resume files?

I'm downloading seve开发者_开发技巧ral files using wget in Windows using the following:

wget.exe -c -P folderName http://something.com/something1.ext

I was connected using a certain IP address, when the connection broke. When I restarted this process, the files were resumed properly. However, when I connected from ANOTHER IP address and restarted the process, the partially downloaded files were NOT continued and wget started downloading all the files from scratch.

Why is wget taking heed to where I connect from and how can I set wget to ignore that?

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This can also be some property set on the web server. In that case you can do nothing about it.