My airport is behaving strangely: internet connection on one device, but no connection on another

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Level 1

4 points

My airport is behaving strangely: internet connection on one device, but no connection on another

My airport is behaving very strangely. This past weekend, without any apparent reasons, the light turned from green to amber. As a result, I wasn't able to connect to the internet on my iMac. However, the internet worked perfectly on my iPad; I was able to surf, watch videos, etc.

I opened airport utility and saw that the DNS server(s) were missing. There was a warning that this may cause problems connecting to the internet. I called my ISP and they said they didn't know about the DNS server(s) because the company who makes the router supplies them, not the ISP. I opened the airport utility again, and told it to ignore the DNS server(s). The light changed back to green. But the internet is still not working on my iMac! Which is very strange -- how can the connection work on my iPad all the way to the laundry room in the basement, but it doesn't work on the desktop which is only 1 foot away?

Also, when I connected the Ethernet cable directly to the iMac, the internet worked. So it's not my iMac. But if the airport is damaged, what made it work on one device and not on another?

Any help to solve this mystery and to get my airport back to work with my iMac is greatly appreciated.

10.6.2, airport 7.6.4.

Posted on Jul 7, 2014 1:18 PM

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Answer 1

Best reply

LaPastenague

Level 9

67,202 points

Jul 7, 2014 2:29 PM in response to Harunotsuki

DNS servers are essential to the operation of the internet. You cannot ignore the error .. you must fix it.

What actual model is your Airport? Actual A1xxx number from the device please.

I recommend you do a factory reset and start over.. many problems disappear this way.

If not then I need more details of your internet modem / router and how the airport is connected to it.

Also, when I connected the Ethernet cable directly to the iMac, the internet worked. So it's not my iMac. But if the airport is damaged, what made it work on one device and not on another?

It the ethernet from the airport or from the ISP modem router??

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Answer 2

Harunotsuki Author

Level 1

4 points

Jul 9, 2014 5:53 AM in response to LaPastenague

I have an Airport Express, model A1264, about 4 years old. Never any problems before. I did the factory reset as you suggested, and it solved the problem. I went through the steps - airport setup, network setup, internet setup - and the internet was back on my desktop. But throughout the process, I did not see any DNS Server(s) fields. (I took screenshots from the first time I set it up, and I didn't see any DNS servers fields then either). If they are essential, how do I find out the numbers? In case a similar problem arises again in the future.

The ethernet cable connects the ISP modem router (Arris TM602G/CT) to the airport on the wall. When the internet didn't work on my desktop, I unplugged the cable from the airport and connected the modem directly to the desktop. I have a great internet service, very fast and never stalls. Sometimes I feel I'm not taking full advantage of it.

Thank you so much for your help. And if you could tell me about the DNS servers (numbers), I'd appreciate it.

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Answer 3

Jul 9, 2014 6:04 AM in response to Harunotsuki

I did not see any DNS Server(s) fields. (I took screenshots from the first time I set it up, and I didn't see any DNS servers fields then either).

When the setup is correct, the appropriate DNS server numbers are automatically assigned. What LaPastenague meant was that DNS numbers are needed for a valid Internet connection, but this is not something that you need to normally think about since the process happens automatically in a correct setup.

It is possible to manually enter different DNS server numbers after the basic setup is complete, but not necessary unless you have a special situation that calls for specific DNS numbers to be used. You would already know what those DNS numbers would be if this were the case, since your Internet provider would have provided these to you in written documentation.

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Answer 4

Harunotsuki Author

Level 1

4 points

Jul 10, 2014 7:31 PM in response to Bob Timmons

Thank you, Bob, for the explanation. If I understand you correctly, provided the setup is done correctly, the DNS server numbers do not show during the setup process. Which was what happened when I re-setup the airport. But I'm still not clear about one thing. You mentioned that my ISP would have provided the DNS server numbers. I did call my ISP for the numbers when the problem first started, and they said they don't deal with DNS servers. According to them, Apple should provide the numbers to me. Things are working well now so I don't need the numbers. But if and when I do need to enter the DNS server numbers manually, whom shall I contact, my ISP or Apple?

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Answer 5

Jul 10, 2014 8:24 PM in response to Harunotsuki

You mentioned that my ISP would have provided the DNS server numbers.

I said that if your ISP has special requirements that require you to enter specific DNS numbers, they would have provided this information to you along with other connection information. The fact that you obtain the DNS automatically tells us that you do not need to worry about entering a specific DNS server number to use.

I did call my ISP for the numbers when the problem first started, and they said they don't deal with DNS servers.

Either the person that you spoke to was just wrong, or you misunderstood what they told you. Every ISP uses DNS servers, either their own or someone else's. Without DNS, you would not be able to connect to the Internet.

According to them, Apple should provide the numbers to me

Apple has no way of knowing who your ISP might be, so it is not possible for them to provide you with information that they cannot know. The AirPort router, and any other router for that matter depend on the Internet connection to tell the router what DNS servers to use. This all happens automatically.....unless your ISP requires you to enter all the connection information manually (yours does not), so you do not need to worry about this.

Want to see the DNS numbers that your ISP assigned to the AirPort router? AirPort Utility will reveal them to you. Are you still using OS X 10.6.2?

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