Can I mix roamed and wirelessly extend in one network?

Will it choose strongest signal or only capable to connect to first primary extreme to extend the wifi?

It will connect to the strongest signal.

Finally express is set to extend wifi „house” but it is only within range of second extreme. Will it be able to extend the wifi? Or it will only extend wifi when in range of first primary extreme? Keep in mind that second extreme is already „extending via ethernet” the first primary extreme.

It will extend the second Extreme.. to a wireless client or extending router, it makes no difference if you have router or extend by ethernet.

In addition to the comments from LaPastenague, you can check to see if both AirPort Expresses are "extending" correctly by opening AirPort Utility.

If they have been configured correctly, both AirPort Expresses will display side by side with both devices connecting via a dotted line.....which represents a wireless connection.

If the AirPort Expresses display "vertically", with one Express connected to the other Express, then the Express at the bottom of the vertical stack is not extending the signal from the AirPort Extreme ac. In fact, it is not "extending" at all....it is "joining" the network, and it does not provide any additional wireless extension in this type of setup.

The reason for this is that Apple's "extend a wireless network" feature will only allow the signal to be wirelessly extended one time, not two. In other words, you can have multiple devices wirelessly extending the signal, but they must all be connecting to the same AirPort device.

Either Express can extend the signal from either one of the AirPort Extremes.

The tricky part comes when you have two Expresses trying to extend the signal from the same AirPort Extreme. In situations like this, both Expresses need to be closer to the AirPort Extreme than they are to each other.

IF....one Express is closer to another Express than it is to the AirPort Extreme, then the signal will not be extended by both Expresses.

I observed that the extending expresses just need to be in range of the extreme to correctly extend its wifi. Their range to each other doesnt matter as long as they both are in range of the extreme

That is interesting, and great if it is working for you, but is not my experience at all when I've done this in past. I have to make sure that both Expresses are closer to the "main" AirPort than they are to each other. If they aren't, then one Express connects to the other Express, with the result that one Express extends the signal from the main AirPort and the other Express does not.

Thanks for the info. I am traveling at the present time, but will test out things with a few spare AirPorts in a few days to see if things are behaving any differently than they were a few months ago when I last tested an "extended" setup with two AirPorts.

As LaPastenague has already pointed out above, Apple's extend setup works on wireless signal strength....for better or for worse.....so if one Express "sees" a stronger signal from the other Express, it will connect to that source, and not the AirPort Extreme that you want.

The general rule of thumb, if you have two Expresses connecting to the same AirPort Extreme, as in your setup......then ideally both Expresses will be about the same distance from the AirPort Extreme......AND.....each Express will be closer to the AirPort Extreme than it is to the other Express.

That way, the strongest signal that each Express picks up will be from the AirPort Extreme.

It's unfortunate that Apple does not really allow users to specify which device they want to connect to which. It's all based on signal strength.

I'll report on my findings when I set things up again to test in a few days.

I don't use express.. but I have several airports and a few TC (which I repair or used to do) so networks grew fairly complicated.. and I can confirm what Bob is saying.. The extend wireless would bounce between sources of signal, and sometimes fail because it would bounce to a unit that was sitting in isolation undergoing testing.

You should not ever need the Express as close as 3M apart .. it is important to realise wireless causes interference to itself.. the more products you add the more wireless sources you have the messier the setup gets.

I did go to great lengths to control the network.. I use different names for the 2.4ghz and 5ghz and force the extend wireless to the 5ghz band.. I also control the channels to ensure I get the best outcome.. when you saturate the signals in an area.. it is going to be problematic.

Let me also commend the old airport utility over the new one. I run Mountain Lion so it is easy to install and use both v5 and v6 utility.. it is much harder since Mavericks.

But v5 utility showed in graphical form links and how good they were. Here is a real setup which was giving issues.. the link between the two airports was 2Mbps and let me assure you that is far too poor to work.. and changing it (by forcing the names) to 5ghz made all the difference.. even with low signal the link at 5ghz was faster and much more reliable.

Some of the info is available in the v6 utility by hovering your cursor over the relevant area of the summary page. That extra little box pops up.. and if you place it over the connection you can see more details.

So hover over good.. where it shows connection and a bunch of info pops up. Speed and signal strength..

But you also should realise this is from the main router perspective.. not the extender..

One of those confusing things.. links can be faster one way than the other.. v5 utility shows actual results from both ends.. v6 utility cannot. I have found significant speed and signal difference end to end..

So if you have a suitable computer or even windows.. and can load up the old utility.. when you are doing complex setups it can be a big help.

In the end.. running ethernet is the right way to do things..

If it is not possible then try Ethernet over power adapters,, called homeplug in US or powerline in UK. We generally just say EOP adapters.

They are not perfect and not always going to work.. but when they do, they tend to be much more reliable than wireless.