Tuesday, May 8, 2007

Offline Blogging

I'm writing this blog entry offline.

When I first moved in, my professor warned me that he didn't think the signal from his wireless router reached the far bedroom in which I'm staying. “That's ok,” I said, “I'm getting 2 bars; not great but it's a usable signal.”

After I'd been using the network for a few days, I happened to mention to him that I'm getting horribly slow speeds on his “linksys” wireless network. “I don't have a Linksys router,” he said. “What?” I asked. “I don't have a Linksys router. I have a D-Link router.” “But... then how... who...” “You must be getting a neighbor's signal.” “Ah. I see.”

Since my connection to a neighbor's internet was both unreliable and slow, I would much rather be on my professor's cable modem connection. I was pretty sure the lack of a signal from his router was a configuration issue rather than a signal limitation, so I went to go check the configuration. At this time it was well after midnight, and not wanting to disturb my professor's sleep, I resolved to hack into the router rather than wake him up and ask him for the password.

In the pitch-black living room, I used the light of my laptop screen to illuminate the mess of cables around his router and cable modem. I'd have to have a copper hard-link until I got the wireless working. I found a spare ethernet port on the router and plugged myself in. Turn on DHCP... then run ipconfig, good: it gave me an ip address. Now that I had a link, I needed to access the router's configuration page. Nine times out of ten, the ip address of a router is 192.168.1.1. I opened up my Firefox web browser and typed in that address. It popped up and asked me for a username and password. So far so good – I wasn't in yet, but at least I knew there is a router at that address.

I never get discouraged when I see a dialog for a password and I don't know it, because I've learned a few very simple facts: 1. most users never change the default passwords, 2. default passwords are remarkably easy to guess. Besides, I had a gut feeling the login would be “admin/admin.”

That brought up the router configuration page. Now, to check the “wireless” section. I clicked on it, but instead of any configuration options, I was treated to this helpful message: ~!@ #$%^ &*()_

The software that is loaded on home network appliances has never been particularly well-written, but lately it has been getting even worse. In this case, the router's configuration software is so badly broken, that it returns a page containing random binary garbage, instead of the wireless configuration page.

Upgrading the firmware on the router to fix this problem would be more work and more intrusive than my original intentions, so I prepared to give up for the night. Then I noticed that the color scheme of the configuration page was purple and grey, rather than the blue and grey D-Link would use. Guess which router company favors puple over blue? Yep, Linksys. I missed the Linksys logo when I first logged in because their broken software just loads an empty image box where their logo goes. But a quick check of the ip addresses on my interfaces showed my error: I should have been on 192.168.0.x if I wanted to connect over my copper ethernet. What I used, 192.168.1.x, was my wireless interface. Darn it, I broke into the wrong router. Sorry neighbor dude! How embarassing – like walking into the Women's bathroom by mistake.

With the correct IP address in my browser, I got to another login screen, this time for the D-Link router. “Admin/admin” didn't work here. Hmmm... maybe, “administrator/password”? Nope. I tried a few more obvious combinations and failed. Time to back up and think about this analytically. Now I know that most login systems don't allow blank passwords, but some do. So perhaps I had been overthinking it. Had I failed to guess the password simply because there wasn't any? Indeed. “Admin/[blank]” worked like a charm.

Once I got into the right router, the only thing I could see that might be wrong was that WEP encryption was enabled. Considering that the router login was admin with a blank password, I highly doubted my professor had been in these configuration pages at all, so I don't think he deliberately enabled WEP. While I would be taking off a layer of security by turning off WEP encryption, if neither he nor I could access his wireless network at all, than the WEP security was clearly not doing any good. As bad as it is to have your wireless network unsecured, WEP has caused me nothing but trouble. Every time I try to use it to secure a network, I've had to turn it back off again because half of the computers I want to connect, can't.

With WEP turned off, the wireless network began working again. Still no internet. Why not?

At this point it's best to approach the problem in stages. Can I ping my own address? Good. Can I ping the router? Good. Can I ping http://www.google.com/? No. What's between the router and google? Ah, yes, the cable modem. Cable modems are notorious for crashing and needing to be rebooted, so naturally they are designed without an accessible reset button and with no on/off switch to power cycle them. How hard would it have been to put a watch-dog timer in the hardware that reboots the modem if it can't ping out? These devices are designed with the assumption that nothing will go wrong. If these companies would admit to themselves that software is inherently unreliable, it would be the first step to making devices that are reliable.

I unplugged the router and waited five seconds before plugging it in. Instead of connecting me to the internet, the router flashed its power and link lights over and over. What the heck does that mean? Turning it off and on again did not stop the flashing. Hmm... If the router has a configuration page, surely the cable modem has one too. How to access it? In the router configuration page, the local network is 192.168.0.x; but the outside network is 192.168.100.x. If that is the network the router is using to talk to the cable modem, that would put the cable modem at 192.168.100.1.

The cable modem didn't require a password, because it doesn't have any user-changeable options. It does show status though. It said “LAN: Up” “USB: Down” (no USB is plugged in) and “CABLE: Down”. Bummer. The modem's event log page had more bad news: “DHCP failed” “Timing Sync Failure” “Failed to receive....” “Failed to receive...” (In other words, the cable modem's not getting any response from the cable company.)

Well, fiddlesticks. After all that, I still have no internet.

It turned out that the cable company was having technical problems; cable internet service was down in the entire area for nearly 24 hours.
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