Airport and Comcast

Question

Airport and Comcast

I have a Comcast modem to access the internet; used the router IP address given by comcast to manually configure the network; then get via DHCP an IP addresses for every computer on my LAN (a mac and several PCs). This works fine as long as I have my ethernet links of my computers are all into the Comcast modem.

I bought AIrport Extreme and switched (only) the Mac ethernet cable to the Airport back and connected the WAN port of the Airport with a regular ethernet cable with the Comcast modem. With this I loose connection to the Internet (ethernet...to ISP still OK; but network fails on Internet access)

Can someone write out in detail how the airport internet connection should be setup Manually (or DHCP) ? what IP address to use e.g. comcast router? How to reconfigure the comcast modem?

Thanks a million

G4, Mac OS X (10.5)

Posted on Jun 22, 2008 10:55 AM

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Answer 1

Jun 22, 2008 11:00 AM in response to guido Deboeck

Sounds like you have it hooked up ok. Run AirPort Utility, select your AirPort Extreme, and then select Manual Setup. Click on Internet and at the very bottom change the Share an IP Address to Off (Bridged Mode). This will allow computers connected to your AirPort and the AirPort itself to be on the same private network as the other computers connected to your Comcast modem. The Comcast modem will still be in charge of assigning DHCP addresses for all computers, including those connected to your AirPort Extreme.

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Answer 2

Jun 22, 2008 11:09 AM in response to Nachos Libres

Thanks for the suggestion. I have put the Connection Sharing to Off Bridge Mode and selected Using DHCP under config IPv4, entered the routing IP of the comcast router for the DNS Server. This still gives me an error.

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Answer 3

Jun 22, 2008 11:19 AM in response to guido Deboeck

What IP address are you using for the Comcast router? It should be its private IP address (i.e. something like 192.168.1.1 or 10.0.1.1) and not its public IP address. I honestly would leave that blank since you are using DHCP to attain the IP address for the AirPort.

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Answer 4

Jun 22, 2008 11:32 AM in response to Nachos Libres

The comcast router is 192.168.1.49. My computers get IP's like 192.168.1.1 and 192.168.1.7 What should I enter under internet in Airport (using DHCP with the rest blank and Bridge mode off)??

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Answer 5

Jun 22, 2008 11:36 AM in response to guido Deboeck

Everything should be blank. What exactly does the error message on your AirPort say? I would also try using some different settings for the Ethernet WAN port (i.e. 10 Mbps/Half Duplex, etc.) to see if that helps any.

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Answer 6

Jun 22, 2008 11:50 AM in response to Nachos Libres

Could I e-mail (address?) you some screen shots from both the Internet window on Airport as well as my network setup (System Preferences)? Whatever I enter I get an error message from airport and my apple TV which is hardwired to Airport does indicate that "it is connected to the internet" but running any of trailers or getting youTube produces errors. Thanks for all your suggestions...Pls mail me your e-mail address where I can send copies of screen shots.

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Answer 7

Jun 22, 2008 11:55 AM in response to guido Deboeck

Joshua.Johnson00@gmail.com

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Answer 8

Jun 22, 2008 12:21 PM in response to guido Deboeck

Ok, on both the AirPort setup for your computer(s) and your actual AirPort Extreme make sure all those fields are blank. I would only use those fields if you are manually assigning your IP.

The error message you referenced has to do with writing to the configuration file, which I don't understand why it won't update. If these steps don't fix your issue I would hard reset your AirPort by holding the reset button for 5-10 seconds and then run AirPort Utility and make sure you put the AirPort back in Bridged mode.

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Answer 9

Jun 22, 2008 1:04 PM in response to Nachos Libres

Finally..... got the Airport Extreme to access the Internet. At least I can view Trailers and YouTube!!!!

The only remaining problem I have is that AppleTV does not show in ITunes.... In iTunes Preferences I got Look for aTV ON. In Sharing I got "Look for shared libraries" ON. In System Pref under Firewall I checked "Allow for essential services" (or should it be allow for all incoming?) The ATV manuel states that if Firewall is on one should make sure that Apple TV Sharing is selected in Sharing of Systems Pref. But I don''t see that listed under services???
Anyone know how to get AppleTV to show in ITunes ?

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Answer 10

Jun 23, 2008 5:31 AM in response to Nachos Libres

Just a short note to say thanks for all your suggestions. I finally got my Airport and Apple TV working last night. The problem was clearly the setup of airport and once that was sorted out, finding out that Apple TV setting needs to "Share iTunes library" before it pops up under iTundes on the mac. Thanks for guiding me thru the most difficult stages of this setup.

Guido

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