Slow Linux Internet? Here is a solution

Some distribution such as Debian etch enable IPv6 by default (I don't know why to use IPv6 now). This may cause the internet connection to slow down as the system searches for IPv6 first and most of internet connections uses IPv4 (which is the appropriate one).

To fix this problem you need to edit file /etc/modprobe.d/aliases to disable IPv6 support. Edit the file and search for the line:

alias net-pf-10 ipv6

and edit it to be:

alias net-pf-10 off #ipv6

Then reboot your machine to enable new settings and enjoy flawless speed.