My Eee PC has been humming along nicely for the past couple of months. Things were going so smoothly that I didn’t have anything to write about. That is, until now. I just returned from a trip to San Jose, California. I was preparing to catch up on my email while I watched the evening news and then it happened. My Eee PC would no longer connect to my home network.
This problem was a quite different from the WiFi problem I wrote about previously. In this case, my working configuration suddenly broke. This is not susposed to happen. There must be a good explanation but, I must find it first.
The first thing I noticed was that my Eee PC was not showing my Wireless access point on the wireless networks list. Instead, the only network I could see was an unsecure network called Linksys. Now it is not unusual for me to be able to see a neighbor’s access point but what was strange was I could not see mine.
I then decided to re-check the configuration file changes I made earlier to make the Eee PC connect in the first place. The /etc/wpa_supplicant.conf_MINE file I generated appeared to be generic so I couldn’t imagine it was causing the problem. The other file I made changes to was the /etc/network/interfaces file. Below the portion of this file that deals with the connection to my wireless network.
iface lan2 inet manual down dhclient3 -r -pf /var/run/dhclient.$IFACE.pid -lf /var/run/dhclient.$IFACE.leases $IFACE down ifconfig $IFACE down up cp /etc/wpa_supplicant.conf_MINE /etc/wpa_supplicant.conf.ath0 up wpa_cli -p /var/tmp/wpa_supplicant reconfigure up ifconfig $IFACE up up dhclient3 -cf /etc/dhcp3/dhclient.$LOGICAL.conf -pf /var/run/dhclient.$IFACE.pid -lf /var/run/dhclient.$IFACE.leases $IFACE wireless-channel 6 wireless-essid Denkigai wireless-key bd8a577135194ff49b51b0602355b252ffd89827c07f477a659c498d0c1c93eb wireless-keymode open wireless-mode auto wireless-rate auto xncs-wireless-encryption wpa
Looking at the wireless configuration, my thought process went something like this:
- I know the SSID of my wireless router did not change (it is still Denkigai)
- I know the encryption type didn’t change (is is still WPA2-PSK)
- I know the wireless key didn’t change (it is too long to type here again)
- What else could have changed? Doh, the wireless channel
I brought up the diagnostic page from my wireless router and sure enough, it was now broadcasting on channel 1. Light bulb moment! I then realized that we had a power outage a couple of nights ago. The router probably picked a new, presumably clear channel when it came up again. I knew there was a good explanation. I went ahead and edited the interfaces file and changed the wireless-channel to 1 and sure enough, the Eee PC connected. I then wondered to myself why I specified the wireless channel at all. I had no problem connecting to public hot-spots without specifying the channel. So I did one final experiment and removed the wireless-channel line all together. I restarted the PC and once again, it connected automatically. Problem solved!
Moral of the story: When setting up a wireless internet connection, do not specify a wireless channel unless you have a specific reason to do so.
Could a hard coded wireless channel explain the WiFi Problems on the Road incident? Perhaps.