Airport Extreme - Create a secondary Wi-Fi Network.

Your setup if fine.

Airport Specs:

Connect using: DHCP

Wireless: Create a Wireless Network w/ WPA2 Personal

Router Mode: Off (Bridge Mode)

Version: 7.6.4

AirPort Extreme 802.11n (3rd Generation)

This is what we would recommend..

If the wireless has failed you simply need to buy a new Extreme.

However I would reset the AE to factory first in case it is suffering from change of network fatigue.. which they do.

If you set the wireless name to the same as the other wifi in the house you will not be able to figure out which is which.. but if you want to test.. let me suggest the following.

Factory reset universal

Power off the AE.. ie pull the power cord or power off at the wall.. wait 10sec.. hold in the reset button.. be gentle.. power on again still holding in reset.. and keep holding it in for another 10sec. You may need some help as it is hard to both hold in reset and apply power. It will show success by rapidly blinking the front led. Release the reset.. and wait a couple of min for the AE to reset and come back with factory settings. If the front LED doesn’t blink rapidly you missed it and simply try again. The reset is fairly fragile in these.. press it so you feel it just click and no more.. I have seen people bend the lever or even break it. I use a toothpick as tool.

Then redo the setup from the computer.

1. Use very short names.. NOT APPLE RECOMMENDED names. No spaces and pure alphanumerics.

eg AEgen5 and use AE24ghz and AE5ghz with fixed channels eg 11, 8, 6 for 2.4ghz and 36-48 then 149 for 5ghz.

Create a wireless network is correct.

2. Test with no password.. if it fails then passwords are not needed.. there is no wireless.

If it works immediately set WPA2 Personal. Use all passwords that also comply but can be a bit longer. ie 8-20 characters mixed case and numbers.. no non-alphanumerics.

These are more issues with Yosemite.. but quoted for completeness.

3. Ensure the AE always takes the same IP address.. this is a problem for you in bridged setup.. however that is secondary to getting wireless working.

4. Check your share name on the computer is not changing.. make sure it also complies with the above.. short no spaces and pure alphanumeric..

5. Make sure IPv6 is set to link-local only in the computer. For example wireless open the network preferences, wireless and advanced / TCP/IP.. and fix the IPv6. to link-local only.

6. No luck then I suggest you take the firmware back to 7.6.1 which was simply more stable. Hold down the option key while you click on the version number.

On the older AE it is more reliable. IMHO!!

I have some standard answers to questions.. I left in the points for completeness.

You can ignore them.. they are irrelevant to getting your wireless up and running..

But they are part of good network practice.

3. AE in bridge gets IP address from the main router.. since this is on a 24 hour lease usually the IP address tends to drift around. This is unhelpful for network setups so you need to set the dhcp in the main router to keep the AE locked to the same IP address.

4. With Yosemite it has major DNS issues.

Read this article which will explain the problem..

http://arstechnica.com/apple/2015/01/why-dns-in-os-x-10-10-is-broken-and-what-yo u-can-do-to-fix-it/

What will happen is the Mac wakes from sleep and discovers the IP Is used already.. it is too stupid to remember that IP belongs to the computer .. so it will give you a warning about duplicate IP address or names.. and it will increment the computer name.. over and over and over again.

In the end your computer lets say is name.. Nickwell will end up being Nickwell (27) .. because there are 26 other ghosts in the system.

I am not really sure what to suggest if you are suffering this problem.. other than you moved to Yosemite too early.. go back to whatever you used to run.