I previously had PIA vpn running on my system and I activated the kill switch for extra security.
However, now I have a new licence and I cannot activate it due to the vpn settings changing my internet and stopping me get through to the internet.
Does anyone know how I can re-enable my internet connection to get through, so i can activate my vpn again?
11 Answer
It is very likely that the PIA VPN kill switch is implemented using iptables. The first thing you can do is check which rules there are in iptables. For that you can use either:
sudo iptables -L
sudo iptables -S.
Both will display all the rules in place, only in a different format.
If you can understand the data displayed and want to remove only a few rules, you can do that with sudo iptables -D. You can combine that command with the results of sudo iptables -S. For example, one of the lines of the output will be: -A INPUT -p udp -j REJECT. To remove that you take everything, remove the -A bit, which meant append when adding a rule, and remove with:
sudo iptables -D INPUT -p udp -j REJECT.
Now, if you are a bit confused about the rules added by PIA (I don't have it, so can't be more specific), you can remove all the iptables rules (have you added any in the past? ufw also works by adding iptables rules), and then let PIA add them back. The way to do this is running both sudo iptables -F and sudo iptables -X to remove and flush all rules. If it still fails and there are still rules left, you can try adding sudo iptables -t nat -F and sudo iptables -t mangle -F. If you can't connect to the internet at all after removing the rules, you might want to add default rules to accept traffic:
sudo iptables -P INPUT ACCEPT
sudo iptables -P FORWARD ACCEPT
sudo iptables -P OUTPUT ACCEPTIt is important to point out that iptables separates the ipv4 rules from ipv6rules, so you want to check and if necessary run the commands with both iptablesand ip6tables.
After all that, and logging back in to your VPN and choosing to reapply the killswitch restart the computer and check the rules, and see if they are somewhat similar to what they were before. It is also good advice to make sure the killswitch is working at all before you rely on it. There is also plenty of other tutorials on iptables if you want to mess with it yourself.
