Our cable modem went down last night, seemingly due to some problems with Comcast’s network. Today, I tried having Adrienne fix it, to no avail. It would give an IP address, but you could not ping the gateway. It turns out that the cable modem has a sort of sleep mode, for people scared of the Internet. Push the big green button, and voila.
The worst part is: While the cable modem is “off” (really sleeping), it still forwards DHCP, so you can get an IP address, but you can’t use it, since it blocks all traffic. So it appears to be working, the network appears to work, but the gateway seems to be down.