Ooma VOIP -> Airport Extreme -> Gigabit Ethernet Switch

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Level 1

5 points

Ooma VOIP -> Airport Extreme -> Gigabit Ethernet Switch

I have tried to search many forums but have not found a solution. Any help would be greatly appreciated.

First, my gear setup, showing the order of connections:

Internet -> Motorola SB6121 Modem -> Ooma Telo VOIP -> Airport Extreme->Linksys SE2500 Ethernet Switch-> Various Devices (DVD/BluRay Player / Synology NAS)

The Airport Extreme is configured to have a Guest network and a Private network. In addition to the devices connected via the Ethernet switch, we have various iOS and Apple computers connected via Wifi to the Airport Extreme.

I have had the above setup for almost three years now with no problems... until just a few weeks ago, which I will describe further below. Before the problem occurred, the Ooma worked flawlessly. The Guest network also worked great; and I was able to access all the devices connected to the Ethernet switch on my Private network.

Here's the problem:

(1) About three weeks ago, the Airport Extreme started to flash amber, with a message showing that I had a Double NAT issue. I don't know why all of a sudden I had this problem, but it may be because of a recent Airport firmware update. After searching the net and visiting several forums for a solution, I swapped the position of the Ooma and the Airport Extreme so that I had:

Internet -> Motorola Modem-> Airport Extreme-> Ooma->Ethernet Switch

This got rid of the Double NAT issue, but then my Oooma was blinking red and refused to connect, leaving me with no phone service.

After spending about 2 hours with Ooma technical support (which BTW was very courteous, professional, and patient as they tried several scenarios), the only way we could get the Ooma to connect was to revert to my original configuration of Internet->Modem->Ooma->Airport Extreme->Ethernet Switch.

To get rid of the Double NAT issue, I was asked to select "Bridge Mode" on the Airport Extreme.

(2) While Bridge Mode solved the Double NAT problem, it led to a second problem: My Guest network was no longer available.

(3) So I turned off Bridge Mode and set the Airport Extreme back to "DHCP and NAT" mode. I then select the "Ignore" option to the Double NAT warning to get rid of the flashing amber light (and get the steady green light).

(4) I thought that I had fixed the problem as now I have both Guest and Private networks functioning, and no more flashing amber light. However,....

(5) ...now...I am unable to see or access any of the devices connected to the Ethernet switch on my Private network.

This has perplexed me to no end as I had not changed my configuration at all. As indicated above, this configuration had worked flawlessly or about three years now until this issue of the Double NAT mysteriously surfaced.

I was wondering if any of you have had similar issues and could offer a diagnosis as to what might have caused the problem I am having. Are there any other settings that I need to do in order to get my network to work as it once did? Mainly, having the following:

1. Guest network

2. Private Network with devices connected via Ethernet switch accessible

3. Working Ooma

A number of Ooma forums suggested DMZ, Enable Default Host, etc.. but I must admit that I am too much of a novice to understand what these mean. I did try a few of these suggestions but they don't seem to work (or I may have just done them incorrectly).

Thanks for taking the time to read to this point and for any advice you have!

iMac, OS X Mavericks (10.9.2)

Posted on Apr 29, 2014 7:44 PM

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Answer 1

John Galt

Level 10

155,810 points

Apr 29, 2014 8:48 PM in response to D Dinh

In your original configuration, your Extreme should have been configured as a bridge, and in that configuration Guest Network is not available. If it was configured to distribute IP addresses using DHCP and NAT (not bridge mode) then you would have had the "double NAT" error.

I realize that is different from what you experienced before these problems surfaced, but it is the normal way of doing things. If it worked for you in the past I have no explanation for that.

A number of Ooma forums suggested DMZ, Enable Default Host, etc..

I agree you're going off in the wrong direction with those choices.

Since this is an Apple support site, and I'm biased in favor of using your Extreme as a router, I can only suggest that you rearrange your network similar to the way you proposed, but with a minor change:

Instead of

Internet -> Motorola Modem-> Airport Extreme-> Ooma->Ethernet Switch

do this

Internet -> Motorola Modem-> Airport Extreme-> Ethernet Switch-> all other wired devices including the Ooma (*).

(*) The Ooma can also be connected to one of your Extreme's LAN ports, if that is physically more convenient than connecting it to the switch.

Ooma will not suggest that configuration for a simple reason: they're biased in favor of using their device as a router. More importantly, by placing the Ooma immediately downstream of your Motorola modem, the Ooma can assign high priority to voice telephone calls whereas the Extreme can't do that.

The effect of this change is that if you are using a significant percentage of your finite Internet bandwidth for activities such as downloading files or streaming video, and you are on the phone with a voice call, the voice call quality may suffer. Ooma certainly doesn't want complaints about voice call quality, which is the reason they take the easy way out and instruct you to put all other equipment downstream of theirs, causing their bandwidth to suffer when the Ooma demands it first. That choice really ought to be up to you though.

Otherwise, their VoIP interface will work fine. It will simply be a client on your network, subservient to the Extreme, like everything else on your network. As long as you are cognizant of the bandwidth limitation, that configuration is likely to resolve the problem (which I realize was unexpected to begin with).

Start by reconfiguring your Extreme, best performed with a "hard reset". Put the Ooma away for now. Make the Extreme work and ensure all your other devices are working. Changing your router changes everything about a network, so be prepared to devote some time to ensuring all the devices on your network operate to your satisfaction.

Then, connect the Ooma downstream of the Extreme, either directly to it or through the switch. It should work as it always has and no reconfiguration should be necessary. Just don't connect anything to its LAN port, because it will still be functioning as a router and the "double NAT" will now be its problem. If it doesn't have any clients that concern will be rendered moot.

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Answer 2

D Dinh Author

Level 1

5 points

Apr 30, 2014 8:41 PM in response to John Galt

John

Thanks for your help. The problem is now fixed, not in the manner that you suggested; but as it was your comment to reset everything that was the catalyst that helped me to resolve my problems. So I'm giving you full credit. Here's what happened:

I placed the Ooma as the last device in the chain as you suggested, but it didn't like that and no matter what I did, I could not get it to connect to the network. Again, Ooma tech support was very patient but they said that they couldn't even detect or ping my Ooma from their end when the Ooma was not connected directly to the modem.

So I reconnected the Ooma back to the original configuration, but remembered your advice to reset everything and so I decided to reset the Ethernet switch as well by unplugging and letting it rest unpowered for about 30 seconds. Lo and behold, that was the solution! All my wired devices are now accessible on my private network. While I still have the Double NAT, I was able to select the 'ignore' option to turn the Extreme light to steady green. Based on what I have read elsewhere on this discussion site, a Double NAT can be safely ignored without compromising the security of my network so I guess I'm all set.

I think you are correct that I have always had Double NAT in my configuration. Perhaps under the previous firmware, the Extreme did not flag this as a warning (blinking amber) and so I never knew there was a problem.

Thanks again for taking the time to help troubleshoot and fix my problem. Very much appreciated!

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Answer 3

John Galt

Level 10

155,810 points

May 1, 2014 8:59 PM in response to D Dinh

Thanks for the update.

In the configuration I proposed it might have been necessary to program the Ooma with your Extreme's IP address for its "default gateway". I think that may be all that was missing. In any event I'm glad you got it working again.

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