Using Airport Express to extend Airport Extreme base station

can I just plug our ethernet into the back of the airport express to give it full bandwidth that it can rebroadcast wirelessly to extend the network?

No, because the AirPort Express has been programmed to expect a wireless signal connection.

If you just plug Ethernet into the back of the airport express, then the Express will "see" both a wireless and wired connection, which will create a huge feedback loop and effectively crash the AirPort Express network.

If you want to establish a wired Ethernet connection from the AirPort Extreme to the AirPort Express........which I highly recommend......you will need to start over and reset the Express back to its default settings, establish the wired connection, then set up the Express again.

This might take a few minutes, but would be well worth the effort, because you will have a much faster and stronger network in the area where the Express will be located.

If you need detailed step-by-step instructions on how to do this, post back to let us know........

1) Whether you will be using a Mac, a PC, or an iPhone / iPad to set up the AirPort Express

2) Whether you have a short, spare Ethernet cable.......any length will do.......to use for the setup of the AirPort Express.

You MUST reset the Express before you plug it into ethernet.. otherwise you will create a loop and bring down your network .. which is what previously happened.

So the steps are as follows.

1. Power on the Express.. no ethernet connection.
2. Once it has been on about 1min.. press and hold the reset button for 10sec until the front LED flashes rapidly.
3. Now plug the WAN port of the Express (assuming later model) into wall.. and setup using the airport utility .. it should automatically detect you are connected by ethernet to the main Extreme/TC and setup to extend by ethernet.

Give it a go.. if you have problems again.. ask..

No need to do massive changes to your network.. just reboot everything if you run into trouble.

Don’t forget, if you’re using an Airport Express to extend an exisitng wireless network (it’s acting as repeater), it will effectively halve the available data-rate.

Also, as mentioned by another contributior, you shouldn’t attempt to connect the ethernet port to your wired ethernet network while the AE is configured as a wireless repeater or client - as, without the benefit of spanning tree protocol, you will create a network loop and/or a broadcast storm that will rapidly exhaust available network resources.

Something is not right. The Express should be able to do at least 60-70 Mbps. I get 80-85 Mbps on the 9 year old Express here as a reference.

Are you sure that your Mac is connecting to the AirPort Express wireless and not the Time Capsule wireless?

You cannot assume that a device located near the Express is actually connecting to the Express if it has connected to the Time Capsule in the past.

Do you know how to check to see to which AirPort your Mac is actually connecting? (Hint.....AirPort Utility cannot always be trusted for this.)

I know there is a client list when using the airport utility so I can check that right?

The "Client List" in AirPort Utility is not always accurate, especially if WiFi devices are changing locations.

If you have a Mac laptop, you can get a much more reliable "read" if you.......

Locate the laptop near the Time Capsule for a few minutes

Hold down the option key on the laptop while you click on the WiFi menu at the top of the screen

Look for the BSSID and jot down just the last few characters

Now walk the laptop to the same room where the AirPort Express is located and perform the same BSSID check

If you see the same BSSID as the Time Capsule, then the laptop is still connected to the Time Capsule. If you see a different BSSID, then the laptop is connected to the AirPort Express

Macs will usually do a nice job of automatically switching AirPorts as the Mac changes locations but most PCs, iPhones and iPads will not do this very well, if they do it all.

For example, if my iPhone is connected to the AirPort in the office and I walk the iPhone to the other side of the house near another AirPort, the iPhone will usually stay connected to the office AirPort most of the time.

Sometimes, it will switch after a few minutes and sometimes it won't. The only way that I can make sure that the iPhone connects to the closest AirPort is temporarily turn off the WiFi on the iPhone, then turn it back on. Then, it will usually connect to the closest AirPort.

How does your MBP or iPhone know when to switch to the closer access point in an extended network?

In theory, the WiFi device should connect to the access point with the strongest signal. In practice, this does not always work as well as the theory suggests, especially with PCs and small mobile devices like iPhones and iPads.

LaPastenague, the expert who responded to your original post first, has said that WiFi in general is a mix of half science and half voodoo. He nailed it.