10 Replies Latest reply: Oct 25, 2014 5:40 PM by Kippster2012
David Stahl Level 1 (0 points)

A few days ago our power went out for a few hours during the middle of the day. I returned home after work by which time the power had been back on for 3 or 4 hours. My wife told me that our internet wasn't working. I figured that I just needed to restart the router and/or modem, but that didn't fix it.


If I plug a laptop into the cable modem, I can get online just fine.


If I plug the Airport Extreme into the modem, the Airport Utility says that the base station does not have a valid ip address and then it tells me that the DNS servers aren't configured.


I've tried restoring both the modem and the base station to factory defaults and powering them down. I bring up the modem and wait for all of the lights to come on. Then I bring up the airport extreme while the ethernet cable is plugged into the modem and configure it like so:


  1. I name it and set the password
  2. I want to create a new wireless network
  3. Set the SSID and password
  4. Share a single IP address using DHCP and NAT
  5. Do not enable guest network
  6. I use a DSL or Cable Modem with a static IP address or DHCP
  7. Configure IPv4 Using DHCP
    1. The IP address as shown is and the subnet mask is I'm guessing this doesn't matter at this point? Everything else is blank.
  8. Then I select "Update"


The airport restarts and I connect to the new wireless network. I notice my amber light is flashing on the extreme.


AirPort Utility tells me I have two problems: my base station doesn't have a valid IP address and that there are no DNS servers.


The page that shows the ip address problem shows a blank IP address and a subnet mask of I can hit "Continue" to skip this and then enter (or not) some DNS servers.


No matter what, I can't get the Airport to get an ip address or get online. I have called Comcast earlier in the week and they claim my modem is working great. I'm about to call them back and see if they'll admit to changing anything.


I tried briefly to get this to work with an airport express that I have in case there's a real problem with my airport extreme. However I couldn't get the express to work, although I didn't spend too much time on it.


Anyone having similar problems or any other ideas to try? I'm located in Atlanta, Ga, in case there's something regional going on. Thanks for any and all suggestions.