GENTOO MIRRORS

The GENTOO_MIRRORS variable - in - contains a space-delimited list of mirror hosts that Portage should use to download source code.

A list of Gentoo mirrors is maintained on the Gentoo site.

Choosing a mirror
A good mirror can make Portage download source code faster. Usually, you can choose a mirror that is near you.

A tool called mirrorselect is available in the Portage tree, and it can help you choose a fast mirror. To automatically select the best five and automatically update, you might use the following:

Alternatively, to interactively choose the mirrors and, again, automatically update your GENTOO_MIRRORS variable you might run:

Autoselect the 3 best mirrors. Deep mode used  to  give  a more accurate speed test. It downloads a 100k file from each server. Output and redirect to anywhere in the file system.