Now that we are a little more up to date after our upgrades, we can have some fun with security. I know that sounds like an oxymoron (like “only choice”), but Security can be fun. I promise.
In this chapter, we are going to implement security rules to permit and deny traffic. Mainly deny because, well, it is easier to test.
To get the real benefit in this chapter (and so that we can do the upgrades in the previous chapter), we need to extend the network again, by adding real Internet access and another Linux node.
Setting Up Internet Access
Start by shutting down the ISP-R router. Connect a new network ...
