4 Replies Latest reply: Dec 16, 2007 10:56 AM by Atlantan
PKGM Level 1 (0 points)
Comcast recently upgraded our modem since we were combining high speed internet and digital voice. I took this opportunity to update my router to an Airport Extreme. Unfortunately it will not work.

I have connected the Ethernet connection from the modem to the WAN port on the Airport Extreme.

I ran the set up and it continues to tell me that it cannot find an IP address.

What am I doing wrong? I need this router to connect my MacBook pro wireless and my G4 iMac which does not have a wireless card.

MacBook Pro, Mac OS X (10.4.10)
  • Tesserax Level 9 (50,080 points)
    Hello PKGM. Welcome to the Apple Discussions!

    With the AirPort Extreme connected to the modem, try the following, in order, until resolved. At each step verify, whether or not, you can access the Internet.

    1. If the modem has a reset switch, use it to reset the modem. Wait at least 5-10 minutes for the modem to initialize.

    2. Remove power from the modem. If it has a backup battery, remove this as well. Wait 5-10 minutes. Replace the battery, and add power back to the modem.

    3. Perform a complete power recycle of your network components as follows:
    Modem/Router Power Recycling - Quick
    o Power-off the modem, AEBSn, & computer(s); Wait at least 5 minutes.
    o Power-on the modem; Wait at least 5 minutes.
    o Power-on the AEBSn; Wait at least 5 minutes.
    o Power-on the computer(s)

    If this fails to get the modem to "recognize" the Internet router, then try the "Full" version.

    Modem/Router Power ReCycling - Full
    o Power-off the modem, AEBSn, & computer(s). (Wait at least 30 minutes. If possible, leave the modem off overnight.)
    o Power-on the modem; Wait at least 15 minutes.
    o Power-on the AEBSn; Wait at least 5 minutes.
    o Power-on the computer(s)

    4. Contact your ISP to have them perform a "modem reset."
  • Atlantan Level 1 (10 points)
    Hope you've got your problem fixed by now. I was in the same situation two days ago when Comcast installed cable at our house and we went from AT&T dsl to Comcast cable. The installers were 30 min. late beyond their 3-hr. window. Then it took about 3 hrs. to do the new installation with me helping some. So when it came time to hook up the computers, I only got the emac hooked up to the RCA dhg535 modem. I figured I could do the airport extreme (AX) hook-up later.
    It had been a year since I had messed with the AX (also I'm pushing 60 and forget a lot), but after about three hours of trying stuff and a second call to Comcast when a helpful lady told me to RESET the RCA modem. That was the key. Just as Tesserax said in his Step 1. But she also told me to unplug the modem, saying nothing about taking out the battery, as Tesserax suggests in a later step.
    When I could not get the AX to connect to the modem, I tried to hook up my son's computer, an imac, directly to the modem. There is only one ethernet-out connection on the modem so if you are going to connect more than one computer, you must use that one ethernet connection to go to the AX. But, first things first, I just wanted to see if I could connect up the other machine directly. I couldn't. That's when I made the second call to Comcast and talked to the helpful lady.
    With all this trouble, I could always connect to the emac--hot-swapping--turning nothing off. When I RESET (using a straightened paperclip to push through the little hole for a few seconds) I was able to connect the imac, but then I could not connect to the emac. So the modem is configured to whatever machine it is attached to AFTER it is reset!
    Then I RESET the modem again and attached it to the AX. Success. I was able to hardwire my emac (it's not wireless) to the AX and connect the imac wirelessly to the AX.
    About connecting . . . it's almost automatic. I did NOT use PPPoE, only TCP/IP with "Using DHCP" from the pull-down menu. I learned that the key initial there is "D" for dynamic--the IP address, subnet mask, and router entries would fill themselves out. I did not have to "manually" enter any numbers.
    Hope this helps someone out; I know I've been helped many times by reading about what others have done.
    By the way, here in Atlanta, Comcast is faster, but now I've got a strange buzz on my telephone line. I'll worry about that tomorrow . . . or maybe next week.
  • jeffrey888 Level 1 (0 points)
    I've tried these tips. I also spoke with Comcast. We did several modem resets, in different ways, and several power downs. I also had Comcast do an automatic modem reset. The modem still won't recognize the AEBSn. Any other suggestions? I refuse to believe that the AEBSn does not work.
  • Atlantan Level 1 (10 points)
    I assume that you are able to connect directly with the Comcast modem to one of your computers. Is that true? If so, you should be able to RESET and then connect directly to your other computer.
    If this is so, you should be able to connect to your AXBSn. Unless, your location and settings are NOT set up properly--I still don't understand all of that well, but I was able to get my AX hooked up.
    If you can't get the AX on line, there is a chance that the fault lies there. Maybe you can get it checked out at the Genius Bar at an Apple Store.
    If the AX is OK, the fault must lie with the Comcast Modem. Wish you luck--my time in **** only lasted for 4 hours.