The other elephant in the room here is that most ISPs won’t let you bring your own router
I almost did a spit take at that. A month ago, our ISP (Optimum/Cablevision) called us about having our old modem replaced, and when we went to exchange it they were really pushing hard their “free” router, despite my having made clear several times that we had no need for it.
I won’t ever be using an ISP-given router, nor wireless, as those run counter to our household sigint policies.
Another thing to keep in mind with regards to using an old “PC” is the vulnerability/performance-hit of that speculative execution bug many are currently discussing. So re-purposing an old PPC/MIPS/ARM/AMD for router/firewall duties should also be an option to consider.
