Q: Will Apple Airport Express work with a Comcast Combination Modem/Router

When you say it's not working correctly, what is happening? Is the Extreme the only thing connected to the modem, or do you have other devices attached to it?

It's possible that you need to put the modem into bridge mode, although technically that shouldn't be necessary - if the modem is also acting as a router you'll still get internet service, but might have problems with multiplayer gaming, or accessing home computers from outside the house.

Matt

Comcast can disable their router functions and put it into bridge mode.

Comcast can disable their WiFi

Comcast can disable their annoying XfinityWifi radio as well

I did all of these with my Comcast WiFi router (it took 2 calls, but all those features were turned off).

Then you should be able to use your Airport Extreme as your home router.  And extend your network with the Airport Express.

As an alternative, you can put the Airport Extreme into bridge mode so that the Comcast router is the home router.  But still extend your Airport Extreme via the Airport Express.  Just be careful to choose WiFi channels for all the different WiFi radios so that they do not conflict (this is one of the reasons I had Comcast turn off their WiFi radio _AND_ the XfinityWiFi radio, because they were conflicting with my Airport Extremes radios).

Another approach is to run Ethernet from the Comcast router to where you want to setup the Airport Express (or since your Airport Extreme is not doing anything any longer, you can use that).  You put the Airport device into Bridge mode, and give it the same WiFi name and password so that you have what is called a "Roaming" network.  Again, make sure you put the different WiFi radios on different channels (5 channels apart for 2.4GHz to avoid conflicts).

If you cannot run Ethernet, you can use Ethernet PowerLine Adaptors as Ethernet substitutes.

Those are some ideas.

You definitely want to follow BobHarris' advice. The Comcast's gateway's WiFi setup will be problematic. Go with the 1st suggested setup.

Thanks for the info Bob. I'm in a pretty similar situation as Mary. I have the Comcast X1 Modem/router in my living room. I have an Ethernet line run back to a back bedroom where my Airport Extreme is. I would like to use that to extend the wireless network for our phones and tablets back there, and also plug our TV into the AP Extreme, I also have a hard-drive connected to it for Time Capsule backups. Should I run it in Bridge mode or no? What should the settings on my AP Extreme be set to in the "Wireless"" tab of AirPort Utitlity?

Thanks so much!!

MacBook Pro 13" Retina (2013) Yosemite 10.10.4

iPhone 6 iOS 8.3

iPhone 5 iOS 8.3

iPad 4

Airport Extreme (2012)

Re: dtmuncy

If the Airport Extreme is just being an extension to the Comcast router (as your description seems to imply), then "Yes" the Airport Extreme should be in "Bridge" mode, as you typically ONLY want one active router in your home.

The Wireless name (also known as the SSID) should be the same as what your Comcast X1 Modem/Router Wireless name is.

The WiFi password should be the same as the Comcast X1 Modem/Router WiFi password.

The 2.4GHz channel used by the Airport Extreme should be at least 5 channels away from whatever the Comcast X1 Modem/Router 2.4GHz WiFi channel is (and hopefully all your channels are 5 channels away from close neighbor's 2.4GHz WiFi; distant neighbors with weak signals do not count ).

And if the Comcast X1 Modem/Router provides 5GHz channels try to get separate between their 5GHz channels and the Airport Extreme 5GHz channels.  The larger the gap, the more likely the 5GHz radios can gang together multiple 5GHz channels for higher bandwidth/faster transfer times between devices in your home, and less congestion when multiple devices in your home are trying to use the 5GHz frequencies at the same time.

You should be able to scan the WiFi signals in your home using

Spotlight -> Wireless Diagnostics -> Window -> Utilities -> Wi-Fi Scan

Then grow the Wi-Fi Scan window so you can see all the columns.

You are going to worry about other strong "RSSI" signals on or near your channel and if the "Noise" for your signal it too strong.

A strong signal is a small negative value: -40'ish is a good RSSI signal.  If there are neighbors on your channel with a strong signal or on an adjacent 2.4GHz channel with a strong signal, you want to move to a less congested channel.

A good Noise value is a large negative value: -90'ish is a good Noise value.  If the Noise moves down to the smaller negative numbers, it indicates you are getting interference on your channel, and you should look for a different channel to use.

Good luck.

Hey Bob, I appreciate all of your replies.  You might have answered my question already so I apologize if I missed it.  Here is what I have:

     Comcast router/modem that is in my basement (I work out of there).  I am trying to get better wireless on my mail floor and a little bit upstairs because i get a decent amount of buffering with netflix, etc.  I just bought an airport extreme and hooked it up to the comcast router.  My house is 20 years old and finished and I don't have ethernet anywhere.  The extreme is right next to the comcast router.

I have a 2nd extreme that is a few years old on our main floor.  How do I get the upstairs extreme to be part of that wireless network as an access point or to "extend" the basement airport?  Right now I have the basement extreme setup to "create a wireless" and i have tried both ways with the upstairs Extreme but neither seem to work. 

Appreciate any help you could offer.  Thanks, Corey.

jugsy15 wrote:

     Comcast router/modem that is in my basement (I work out of there).  I am trying to get better wireless on my mail floor and a little bit upstairs because i get a decent amount of buffering with netflix, etc.  I just bought an airport extreme and hooked it up to the comcast router.  My house is 20 years old and finished and I don't have ethernet anywhere.  The extreme is right next to the comcast router.

I have a 2nd extreme that is a few years old on our main floor.  How do I get the upstairs extreme to be part of that wireless network as an access point or to "extend" the basement airport?  Right now I have the basement extreme setup to "create a wireless" and i have tried both ways with the upstairs Extreme but neither seem to work.

 

The bad news is that I am away from home at the moment, so I cannot fire up Airport Utility and find the exact information for how to do this.

But what you want to look for is something that says Extend an Existing network.  You might start with this web page

<Wi-Fi base stations: Extending the range of your wireless network by adding additional Wi-Fi base stations - Apple Suppo…>

and then do some Googling on "Airport Extreme extend wifi network"

An alternative is to use Powerline Ethernet Adapter to get Ethernet upstairs.  But first work on extending the existing WiFi network and see if that works for you.

I just bought an airport extreme and hooked it up to the comcast router.

You don't mention whether this is working correctly, but we will assume that it is, correct?

The extreme is right next to the comcast router.

If possible, it would be better if you could separate the AirPort Extreme and Comcast router by a few feet, or about 1 meter, to reduce the chances of wireless interference occurring between the two devices.

I have a 2nd extreme that is a few years old on our main floor.

Got that. The 2nd Extreme on the main floor must be connecting to the basement Extreme using wireless.....since you say that Ethernet cabling has not been run anywhere, correct?

How do I get the upstairs extreme to be part of that wireless network as an access point or to "extend" the basement airport?

This is where we get confused. Is the "upstairs" extreme the same Extreme as the "main floor" Extreme?  Or, is there another AirPort Extreme that is "upstairs" from the "main floor" Extreme.....meaning that you have an Extreme on the "main" floor and yet another "upstairs".......in addition to the basement Extreme?

1) We need clarification on exactly what you have and where the devices will be located.

2) We need to know what operating system you are running on your Mac or PC that will be used to set up the Extreme(s).

You should be able to extend your network over WiFi using:

on the Upstairs Airport Extreme.

I had to remote screen share into my home network to even get this screen shot, and I was NOT going to actually try to enable this so I could verify all steps.

As I said in my reply above, you can also use "Powerline Ethernet Adapters" to get an Ethernet jack to the Main floor or even to the 2nd floor if you desire, and then setup the 2nd Airport Extreme in "Bridge Mode" for a roaming network, as explained in one of the much earlier replies.

FYI: If you're going to put the Comcast Modem into bridge mode then you can also save yourself $15/month by buying a cable modem from best buy (for example) and returning the Comcast crappy modem/router.

Sorry for the confusion.   I have Comcast in my basement and my extreme is next to it.  I then I have another extreme on the main floor, nothing planned for the 2nd floor.  OS is Yosemite 10.10.5 and I am setting up the network on an IMAC (late 2013).

Great advice from everyone, really appreciate it.  I will give it a shot and see what happens.  Here is what I have now:

    Comcast router is functioning and so is the wifi. The basement Extreme is connected to the Comcast and setup as (create a wireless network) with the same name and password as the Comcast router.  I think at some point I probably need to call comcast and have the turn off the wifi or move it to bridge mode.  For now those 2 routers are working though.

I will see if I can get the mail floor extreme to extend the network.

thanks again.

The basement Extreme is connected to the Comcast and setup as (create a wireless network) with the same name and password as the Comcast router.

As long as Comcast is acting as a router, you should have the Airport Extreme in "Bridge Mode", as you do not really want multiple routers in your home.

If you have Comcast put their router into Bridge mode, then you would take the basement Airport Extreme out of Bridge mode.

I suspect that the main floor Airport Extreme when setup to Extend a Wireless Network, will automatically be in Bridge mode, but you might want to double check that.

And since you will have 3 active WiFi devices, you should be checking all the channels being used with the Wireless Diagnostics utility (see my Jun 12, 2015 2:15 PM  reply above).  Another way to get there is Holding the "Option" key -> Click the WiFi menu icon -> Wireless Diagnostic and then follow the advice from above.

I will see if I can get the mail floor extreme to extend the network.

Here is one way to do that using your Mac.  If you have an iPhone or iPad handy, that device could be used as well.

Temporarily, move the "upstairs" Extreme to the basement or close proximity to the basement AirPort Extreme.

Power up the upstairs Extreme for a minute or two

Hold in the reset button on the back of the Extreme for 5 to 6 seconds and release

Allow a full minute for the Extreme to restart to a slow, blinking amber light status

On your Mac.....

Click the WiFi icon at the top of the screen

Look for a listing of New AirPort Base Station

Click directly on AirPort Extreme

If you are using an iPhone or iPad.....

Tap Settings on the home screen

Tap WiFi

Look for a listing of Set Up AirPort Base Station

Tap on AirPort Extreme

That will get the setup 'wizard" running. It will take a few seconds to analyze the network, then display a screen that looks like this....except that you will see your devices pictured and network name displayed

Enter a device that you want to call the upstairs Extreme

Click Next

The setup wizard will configure everything for you. When you see a message of Setup Complete, click Done.

Now move the Extreme to the location where you want it upstairs. The more that you minimize obstructions between the AirPorts, the better the network will operate. If you want the best performance from your network, you will need to run an Ethernet cable from the basement Extreme to the upstairs Extreme and then set up the upstairs Extreme again.

Bob:

You seem very knowledgeable about this general topic.  I have a related issue that keeps coming up that you might have some insight on.  First, my set-up.  I have a Comcast X1 Gateway that functions as the router and the home phone.  The cable feed from the street connects to this Comcast modem in the basement home run.  I have a wired network throughout the house that is powered by a Netgear multi-port switch at the home run.  I have 2 Airport Extremes operating in bridge mode that are wired to the network on the first and second floors to lines that ultimately go to the switch.  The Airport Extremes provide the wireless network.  Although the Comcast Gateway wireless is on, none of my devices connect to it. I should say that I have a number of devices hard wired in my network including multiple smart TVs, Sonos units and desktop computers.  The problem: occasionally, my internet connection goes out on all devices including the wired ones, but will cycle on and off for a period of time.  It is very unpredictable and shows no consistency.  Comcast did a bunch of troubleshooting over several visits and got nowhere.  The other day, I did some experimenting during an outage and I disconnected the 2 wired connections from the switch that go directly to the Airport Extremes on the upper floors.  The internet connection came back online.  That got me spinning.  Fact is, the current configuration works well for relatively long time periods, but ultimately reverts to this temporary outage pattern.  I guess this is some sort of interference issue, but this outage happens on my wired connections as well.  Somewhere there is a conflict in this set-up that is not always problematic.  I would appreciate your insights on what the best set-up would be to potentially solve this issue.

Should I run the Comcast modem on bridge mode and add a third Airport Extreme to the home run in the basement to function as the router to power the switch?

Should I change the settings on the Airport Extremes to make them more "compatible" with the Comcast router function?

Any other proactive ideas that I have not thought about?

Thanks, Jim