Can Old Laptops Be Routers Too?

Porthos writes "There are several HOWTOs about installing Linux on laptops and several more about turning old P75s into Linux-based routers/firewalls, but I haven't heard much about turning old P75 laptops into Linux-based routers." Is there any reason to disrecommend a laptop as a router? I know people with their old portables running as servers, routers, and everything else ...

"As best as I can tell, an old laptop would make a perfect Linux router. You have a notebook-sized machine that has it's own monitor, mouse, and keyboard that easily hide away when the machine is not in need of human attention. Furthermore, most laptops have two PCMCIA slots to accommodate the two necessary network cards. My old WinBook XP even has a built in modem for dial-in access, should the situation demand it.

If the power goes out, a notebook computer would keep running for anywhere from 30 minutes to two hours. This would allow any critical systems to complete their tasks, assuming that they are on a UPS. And if you need to use such a setup at an alternate location, you could just pickup and go with the laptop.

My question is this: Is there a downside to using an old laptop as a Linux-based router? Obviously you wouldn't use such a device in a large-scale office setting, but could this be a viable alternative to picking up one of those $130 Linksys Cable/DSL routers? If not, why not?"