slow internet after kernel upgrade

You recently upgraded your Linux kernel or changed your distro and Internet became suddenly slow ? You tried everything from disabling ipv6 support, MTU improvement to DNS tweaks ?

Generally the connection behaves normally for a few minutes and then speed dramatically decrease

Well if you’re using Wifi (especially an Atheros chipset), it’s probably a stupid module problem try typing:

sudo modprobe -r ath5k
sudo modprobe ath5k nohwcrypt

Now check if the connection is as fast as usual, if it’s OK, you can make this modification permanent using this command (tested with Ubuntu) :

sudo sh -c "echo 'options ath5k nohwcrypt' >/etc/modprobe.d/custom-wireless.conf"

Enjoy fast surfing!