On my Debian Wheezy system I noticed very slow HTTP connections, for example while using
wget. The problem was somehow related with the uncomplicated firewall (ufw), since it only occured while the firewall was running. After searching forums and mailinglists, I found the advice to turn off IPv6 support, which turned out to be the solution (or at least a workaround).
The Debian Wiki shows how to disable IPv6 support in
/etc/sysctl.conf by adding the follwing lines:
Find out which network interfaces you have by using
Of course, a better solution would be a working ufw with IPv6, but for now IPv6 is not important for me and I hope that ufw will introduce proper support for it soon.