Disable & Verify Firewall

Fedora 20/21/22/23
Disable/stop Firewall systemctl disable firewalld.service systemctl stop firewalld.service Can be undone with "start" and "enable".

Check Firewall in Fedora 20/21/22/23 systemctl status firewalld.service

Fedora 16
Add /bin/bash to /etc/shells as the vsftpd yum install does not do it correctly causing tftp timeout message

Debian/Ubuntu
sudo iptables -L

If disabled, the output should look like this:

Chain INPUT (policy ACCEPT) target prot opt source destination

Chain FORWARD (policy ACCEPT) target prot opt source destination

Chain OUTPUT (policy ACCEPT) target prot opt source destination

Disable Ubuntu Firewall sudo ufw disable

Disable Debian Firewall iptables -F iptables -X iptables -t nat -F iptables -t nat -X iptables -t mangle -F iptables -t mangle -X iptables -P INPUT ACCEPT iptables -P OUTPUT ACCEPT iptables -P FORWARD ACCEPT

Other debian settings:

/etc/hosts.deny

This setting in the above file will deny traffic from any source except locally:

ALL:ALL EXCEPT 127.0.0.1:DENY

Comment out this line like so:

#ALL:ALL EXCEPT 127.0.0.1:DENY

Windows 7
Start -> Control Panel -> View by "Small icons" -> Windows Firewall -> Turn Windows Firewall On or Off -> Turn off all three.

Configuring firewall on Linux
To set the firewall for Linux to only allow what is necessary, please see the FOG security article.