How can I safely reset my network settings?

[zahtar]

Hello everyone! Following the situation on this topic,

https://www.kubuntuforums.net/forum/...ering-password

I contacted the nordvpn support and the representative asked me to enter these commands, which I do not understand how safe they are.

Am I cancelling any protection from my pc this way?

sudo iptables -F INPUT
sudo iptables -F OUTPUT
sudo iptables -P INPUT ACCEPT
sudo iptables -P OUTPUT ACCEPT
sudo iptables -F -t mangle
sudo systemctl restart NetworkManager​

Any help is appreciated!

Thanks in advance!