The necessary information to enable others to help you will of course vary with the problem for which you are seeking help. But here are some minimum guidelines, for users of the #netfilter channel on freenode.net IRC. First off, it’s always a good idea to put a summary of the problem and goal in your […]
Category Archives: Netfilter
A quick run down on iptables rules
What is it? iptables is a cli frontend to netfilter, the Linux kernel firewall/nat implementation for OSI layer 3 and 4.
iptables best practices
Don’t use iptables to apply your rules one at a time, use iptables-restore to apply a whole ruleset in one action. Set your INPUT and FORWARD policy to DROP. Don’t set your OUTPUT policy to DROP unless you really know what you’re doing. If you’re going to implement a blacklist or whitelist, you should look […]
Summary page of the Netfilter related resources
Summary page of the Netfilter related resources iptables 101 and FAQ to get started quickly iptables tutorial from frozentux flowgraph of the packets in netfilter as png or svg Managing large lists of IPs,subnets, protocols or ports in iptables using ipset Dynamically updating ipsets from DNS records Periodically updating a blocklist from an IP using […]