Linux as a WAN router

I will discuss the issue of placing a Linux machine as a router, and some special cases where things might play a bit different. The most common scenario is of placing the Linux as some sort of PPP or DHCP-via-cables router. It might look like this: In this picture, the Linux machine actually recieves, via…

Linux IPTables flow

IPTables can be tricky. The concept of chains pointing to chains pointing to chains can get complicated. However, understanding the initial flow, the initial “which chain points where”, and the general concept which can allow, later, for easier NAT, or DNAT, or even knowing where to put a single rule is important. Especially if you…