Iptables is a powerful utility for controlling network traffic coming through your host. But writing the rules that control the flow can be hard to troubleshoot when you have a complex network and multiple host interfaces. Luckily, you have the ability to insert log rules wherever necessary to get visibility into the packets flowing through … Ubuntu: Debug iptables by inserting a log rule
There are multiple approaches to allowing a process to run as a non-root user but still provide access to privileged ports (<1024). There are applications like Apache that handle this by starting the master process as root, and then worker processes as a less privileged user. Another way is setting the privilege on a binary … iptables: Running service as non-root, iptables to forward from privileged port
In previous articles I have described how to use a Squid proxy as a bridge to outside services such as http and ftp. Having hosts in your private networks use a single access point to services in the outside world institutes the type of control often required in production data centers. Having a single host … Ubuntu: Using iptables to forward tcp and udp requests