Q: Roaming network Time Capsule and Express - internet drops out when I connect the Express by ethernet.

Just a few questions, and we should be able to get you going in short order.

We assume that the "main" base station is operating correctly. Is that the case?

What operating system are you using to configure your AirPorts? If you have a Mac and are not sure, click the Apple icon in the upper left corner of the screen, then click About This Mac. Post back with the OS X Version number that you see there.

Or, you might be using an iPhone or iPad of the setup. Please confirm on that.

Have you tested the Ethernet cable that connects to the AirPort Express to make sure that it is operating correctly? If yes, how did you test?

If you can post the models of Airport devices you are using, that would be very helpful. I have had issues with dual-mode Extremes and the second generation 802.11n Express interoperating in a Roaming network. It may be just my experience, though.

One piece of software that may be helpful is iStumbler, which can show RSSI and other details for each AP in a roaming network.

OK, thanks for the clarification.

I assume that you have confirmed that the Ethernet cable from the Time Capsule to the Express is working by temporarily turning off the wireless on a laptop, connecting the Ethernet cable to the laptop and checking to make sure that you can get a good Internet connection that way.

If you can, the Ethernet cable is working. If you cannot get an Internet connection during this test, you cannot proceed until you have the Ethernet cable working correctly.

Disconnect the Ethernet cable from the Express if it is connected, but leave the Express powered on

Hold in the reset button for 8-10 seconds and release

Allow a full minute for the Express to restart

Now connect the Ethernet cable to the WAN "O" port on the AirPort Express

Open up AirPort Utility

Click on Other WiFi Devices

Click on AirPort Express

The utility will suggest that the Express be setup to "extend" the Time Capsule network. Go ahead and accept that for now, and type in a device name that you want to use for the Express, then click Next

The utility will setup everything for you automatically. Watch the screen carefully to confirm that the Express is being set up to "extend using Ethernet".

When you see the message of Setup Complete, click Done.

The Express is now extending the Time Capsule network using Ethernet. You can move your computer from the area near the Time Capsule to the area near the AirPort Express......and stay on the same network.......but pick up the stronger signal from the Express.

If you want to assign a different name to the network that the Express is broadcasting, post back. If you do this, when devices move near the AirPort Express, they will have to log off of the Time Capsule wireless and log onto the AirPort Express wireless network.

Is that what you want?  If so, we can provide the steps to change the settings on the AirPort Express.

By the way......the problem that you were having before was that you first setup the Express to extend using wireless......then you connected an Ethernet cable to the Express (which was expecting a wireless connection) and that wired connection created a massive feedback loop on the network. Basically, a crash.

Hi Bob--

Thanks for helping us out. I have been having issues with lost internet connection with the current gen Airport Extreme. I too was trying to extend my connection over ethernet to a previous gen Airport Extreme (created wireless network w/ same name/pw as main Airport Extreme) and a current gen Airport Express (set to bridge mode with wireless disabled just for the AirPlay functionality), and it worked great for weeks, and then has suddenly crapped out on me this week. My internet connection grinds to a halt over a period of minutes until its down to nothing. However, when this happens, all I have to do is take the ethernet cable that's connected to the modem, and connect it directly into a computer instead of the AE, and the internet is back to 20Mbps without a reboot of the cable modem or computer or anything. The internet bandwidth is just there waiting for me, but my AE is pinching off my connection to it.

With that happening, I streamlined my network down to just the current gen AE base station connected to the modem. Same thing has been happening even with the streamlined setup. It'll work for a few hours, or overnight if I'm lucky - but then, without much warning, will grind to a halt. All I have to do is connect my Mac directly to the modem, and I'm back in business. I've gone so far as to pull an old 2006 MacBook out of retirement to serve as a temporary base station by connecting it via Ethernet to the modem and sharing connection to my other computers and Apple TV by enabling Internet Sharing. Works SO well and never slows down!

I've talked to Apple support, and they were helpful in getting things running again, but less than 24 hours later, it stopped working again. They tried to tell me to setup my previous-generation airport extreme to extend the network wirelessly because I live in a small NYC apartment, and the close proximity could be confusing the devices. I protested, saying that this would reduce overall throughput, but they insisted, and I couldn't argue because it did solve the problem... for a while. It's back, and nothing I try can fix it. I've even tried setting up the previous-gen airport without wifi enabled. Just hardwired to the main basestation, and then hardwired to a couple desktop macs. This fails too.

The issue HAS to be with Airport.

For the heck of it, I tried the instructions you have above, to reset the airport and tell it to extend over ethernet. I did that, but when it finished, it had created a new wireless network with no password! Why would that happen? Shouldn't it be trying to blend with the main basestations wireless network to create the roaming effect while relying on ethernet for max network throughput?

Appreciate any input you might have!

A Roaming Network is typically...

Main Router -> AP1 (Bridged via Ethernet) - Same SSID/Password - say Living Room

Main Router -> AP2 (Bridged via Ethernet) - Same SSID/Password - say Bedroom

The 'old' Airport utility (5.x) used to show this setup before saving it as a 'roaming' network, because the devices would send beacons looking for strong signals and switch. The requirement is that they should share the same IP address space/DHCP server and be routed via the gateway. This is a very simplistic explanation. There are standards like 802.11r and 802.11k which further specify a lot of other details in terms of authentication, etc. otherwise your neighbor can also clone and steal your stuff similarly.

Here are 4 network diagrams w/ config info. They represent an abbreviated summary of the network layouts/configs I've tried.

Not sure if the forums will let you view this at full size when embedded, so here's a link to the diagram on dropbox:

https://www.dropbox.com/s/rr4bbunx5tdvls1/Apartment%20Network%20Layouts.png

The Original configuration should have worked (even though I would make a few small changes).

I had an 802.11ac (bridged - ethernet to main router) which was in a roaming network with two 802.11n 4th gen TCs and was not working for me.

Have you considered swapping the Airport Extreme and the 802.11ac unit? Since you are in an apartment, higher antenna power will create more problems than solve it.

The Trendnet is a 5-port gig switch. If you connect the 4 airports to it (all WAN ports of airports) and connect the ATV to any of the Extremes/Express devices, the remaining port can go to the TWC modem. Is the modem capable of DHCP (what model is it)?

I do not know what your SSID configurations are, but in an apartment 5GHz should work well, leaving the 2.4 for older iPhones, etc. I would not allow any b/g devices on the network unless I had to. There is also a group key rotation interval, which in my case set to 8 hours.

The TWC modems can drop connections if they do not see any DL activity. Where is your NTP pointed to for these Airports?

If you have the older Airport Utility 5.6 (excluding the ac and the new n express), they can generate syslog and SNMP when set, which may help debug drops.

One other option is to give static IPs to all airport devices (or even all devices) eliminating DHCP lease issues on the LAN side. Any visiting device can be  given a small block of 16 IPs out of say 192.168.1.129-255.

Just some experimentation and ideas that you can explore further. The shared internet connection via the laptop is a very strange solution, but it works.

You may want to start a new thread to discuss further, if you like. Bob, Tesserax and others can provide valuable input.

I am a big fan of iStumbler, so it might be worth a try in your situation.

iStumbler is good.....and it's free!  But, you have to do the math if you want to come up with SNR figures for a network.....unless there is a new version that I have not seen.

WiFi Explorer and WiFi Scanner do the math for you on SNR.....but they cost a few dollars. 

Thanks, Bob. Good to learn some new stuff. Will try these two.

Thank you so much for your detailed response Loner T!

Here's the config I'm currently testing, including the performance status. I eliminated the AP a/c from this entirely.

Next config I'm going to try will be the same, with the exception of disabling wireless on the bedroom airport, per your note about power. I'll start a new thread like you recommended after that.

The modem doesn't seem to offer DHCP. When I plug everything into the switch, nothing gets an IP address. I have devices alive on the network all the time. Not pictured here are two iPhones. I work from home most days too, and use dropbox for all work w/ remote teams so between all that, there's rarely if ever a lull in network transmissions.

I tried setting up the switch as a buffer between the modem and airport extreme a/c (per someone's recommendation in these communities regarding WAN ports being fussy on the new extremes). Very promising at first, but it completely failed after about 16-20 hours. That was the last thing I tried before I joined this convo.

I read about iStumbler - much respect for its creator - read an interview with him full of good info a couple weeks back. I'll give it a try after give Airport Util 5.6 a whirl. Will be worth more than $20 if it fixes this for me!

Thanks again.

These look great! Thanks Bob. Would you recommend one over the other?

No, but I think WiFi Scanner might be a bit prettier, with more colors to look at.