Greetings, I am in the process of learning Netfilter/IPtables. I plan on using Netfilter/IPtables to protect my Linux desktop computers and servers. We're talking host-based firewalls, not one firewall protecting all of the desktops and servers. I have a basic question I am hoping someone on this mailing list can answer. I am a little confused about configuring Netfilter/IPtables on a Linux desktop computer. Specifically, this situation: a linux desktop computer that is configured to use DHCP and configured to use the following rule: $IPTABLES -A INPUT -s $IP_LOCAL -j LOG --log-prefix "Spoofed source IP" $IPTABLES -A INPUT -s $IP_LOCAL -j DROP I would like to include the previous rule as part of a standard rule set. >From how I understand this situation, the firewall would have to be able to automatically detect when the computers IP address changes, right? Manually inputting the computers IP address each time it changes would get really old. I'm using several books as references for learning Netfilter/IPtables and they discuss implementing "dynamic firewall scripts". In this case, a dynamic firewall script that recognizes when the computers IP address changes. So, my questions are: 1.) If I am using a computer that is configured to obtain its IP address through DHCP, what firewall rules do I need to setup? 2.) Additionally, how do I configure the firewall to automatically detect changes in the computers network configuration (IP address change, etc.)? Thank you for your time, *Nick*
