Cloud firewall disables CentOS firewall? Or iptables not in kernel?

April 5, 2018 516 views
DigitalOcean Cloud Firewalls Firewall CentOS

Some time (not sure how long) after I set up my Cloud Firewall, I discovered that the built-in iptables firewall in my CentOS droplet has stopped working. I have this message in diagnostics:

iptables v1.4.21: can't initialize iptables table `filter': Table does not exist (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.

Is this typical? I upgraded the kernel about two weeks after the SPECTRE/etc. reports came out, not sure if that is part of the scenario either.

1 Answer

The module certainly should be there and the cloud firewall should not have any effect on your ability to launch iptables on your droplet(s).

Doing a bit of searching, there are others who have encountered this issue on CentOS and by ensuring the module is properly loaded they have resolved this issue:

sudo modprobe ip_tables
sudo echo 'ip_tables' >> /etc/modules
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