I have 31 devices with IP addresses in my house right now. 4 computers, a printer, a game console, a router. These I expect. But also 6 Sonos music players, 3 Roku video players, 3 DirecTV boxes, 3 TV displays, and a couple of iPhones and an iPad and a Kindle. And several other devices on my network I can’t readily identify. I’m a geek who collects gadgets, sure, but I don’t think I am particularly extraordinary in that. This proliferation of devices presents several problems.
The first problem is basic network management. The only reason I know this count is I’m enough of a geek that I know how to find my router status page. Some routers I’ve seen only assign 32 IP addresses in total, I wonder how many households hit that limit and have no way of knowing? How does anyone even know what is on their network?
The second problem is tracking down problem devices. For me this usually shows up as “something’s using all the fucking bandwidth” on my slow 1MBps connection. So I look at the router IP traffic display to find the problem IP address. Then the question is, what is the device? If I’m lucky the device asked for a name when registering via DHCP; the name “DIRECTV-H25-9B3FDEB9” is a pretty good clue, and I’ve learned “NP-1GH314015312” actually means “Roku”. Sometimes the MAC address is a clue; you can look up the first 3 bytes to find the vendor. But knowing an ethernet interface was built by “Hon Hai Precision Ind. Co.” isn’t that helpful. Google tells me that’s Foxconn, still not helpful, it took something else that made me realize that was really my Playstation 4. My Kindle shows up with a prefix E0:CB:1D which is “private”, completely useless for identification.
So then I have to get clever to find the device. nmap’s TCP fingerprinting is helpful for figuring out what OS that IP address is running. For the Playstation that showed that it was FreeBSD, and I vaguely remembered that Sony bizarrely used FreeBSD for its OS and that helped me track it down. nmap can’t detect the Kindle OS via TCP fingerprints. For that device I was left with wireless signal strength in my router display. I guessed maybe it was the Kindle by the time it registered for DHCP then physically carried the Kindle nearer to the router to determine the mystery IP address’ signal strength got stronger. Ridiculous.
The third problem is some devices can’t be trusted with Internet access. My Samsung TV displays are in that category, their SmartHub SmartTV crap. Actually in theory I like the idea of it and the Netflix client etc aren’t bad. But there’s lots of reason to be worried about the security exposure of TV firmware. Also the UI is terrible. Samsung thinks the best time to pop up a “do you want to update?” dialog is right when you turn the TV on after dinner and are about to watch a movie. Consumers can’t even meaningfully answer that question; why ask it of them in the most intrusive possible way? Anyway, I decided the TVs didn’t need Internet access anymore. Not easy to disable. For the wired TVs it was enough to unplug the ethernet, but for the wireless ones the OS lacks any way to forget a network. Fortunately I could tell it to use a new bogus SSID and it was literal enough to accept the broken network even though it knew about a working one.