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Airport Extreme Base Station and new Comcast Cable Modem

P

pianoman88

macrumors regular
Original poster
Aug 20, 2010
218
57
I upgraded from a personaly-owned cable modem to a Comcast's latest cable modem only to discover that I can't use my Airport Extreme anymore: the light yellow light flashes continually. I'm using Comcast's wireless connection at the moment but I don't like the idee of having to use someone else's password.

Suggestions?
 
I am on comcast using a docsys 3 ARRIS modem and the extreme with no issues.

Are you sure your new modem is properly provisioned on Comcast?

Did you buy it or did Comcast provide it?

If its your modem you have to get it provisioned by calling Comcast.

If that is not the case, then perhaps you have not specified an incorrect network key?
 
pianoman88 said:
I upgraded from a personaly-owned cable modem to a Comcast's latest cable modem only to discover that I can't use my Airport Extreme anymore: the light yellow light flashes continually. I'm using Comcast's wireless connection at the moment but I don't like the idee of having to use someone else's password.

Suggestions?
Click to expand...

What error are you getting in the airport app. It should say something like no Internet, or no DNS, or double NAT.

Try setting the Internet in the airport app to DHCP and set DHCP and NAT too off in the network tab.

Also you could try resetting the AE and let it pick up the best config automatically.
 
pianoman88 said:
I upgraded from a personaly-owned cable modem to a Comcast's latest cable modem only to discover that I can't use my Airport Extreme anymore: the light yellow light flashes continually. I'm using Comcast's wireless connection at the moment but I don't like the idee of having to use someone else's password.

Suggestions?
Click to expand...

You need to do one of two things.... either figure out how to put the Comcast modem/router in bridge mode, or just put the Extreme in bridge mode.

You can set the Extreme to bridge mode using Airport Utility (screenshot below).

ZKpfOjT.png
 
Just went through the same thing last week. It's double Nat because you're basically hooking a router to a router. You have to call comcast and have them put the new gateway in passive mode I think it was called. Just tell them you want it to act as a modem not a router. I actually did this via the chat Window that pops up when you log into you're comcast acct.
 
Comcast modem to Airport Extreme

So.. my Airport Extreme just arrived in the mail. I am guessing that I am in for it when it comes to trying to get this to work by Friday when my Xbox One arrives. Any suggestions? As of tomorrow I will contacting Comcast to see if they will change my new gateway to passive mode. Any other suggestions?

Thanks
 
I just go online and buy my own modem.

Why pay some stupid leasing fee forever when you can own your own and then sell it when you don't need it anymore. Plus you'll most likely be using the service for a couple years, so owning it is still a better option.

Plus you can get one without a built-in router.


Anyways without knowing which modem you have right now, it's hard to give exact steps, but you want to turn off the routing functions of your current modem to use the AirPort Extreme as your router.
 
RegularJizzo said:
As of tomorrow I will contacting Comcast to see if they will change my new gateway to passive mode. Any other suggestions?

Thanks
Click to expand...

In my experience, the magic word with Comcast is "Bridge Mode".
(and it works - I even got my old IP address back)

A.
 
Pairing COMCAST wireless router with Airport

Because COMCAST's modem is on another wall of the room from the Airport modem, the COMCAST Modem is not reachable with an Ethernet cable from the Airport.

After starting Airport Utility, I got this message:

"No configured Airport base stations have been found"

The COMCAST rep configured their Gateway/router wirelessly with my new iMac ... and the internet works just dandy, but constantly blinking orange light on the Airport.

BY THE WAY, I did a hard reset via the pinhole on the back of the Airport and it momentarily brought up configuring the Airport. But, with a restart, back to square one.
 
I also just upgraded my Comcast modem w/ wifi. You can change the password. You need to go to http://10.0.0.1, log on w/ admin and password as your password. Then click on 'change password'. You can also change the name of the wifi network for the Comcast modem and it's password.

I use an Airport Extreme as well. I have it set up in Double NAT in order to create a working guest network. Other than the Double NAT warning which I just clicked ignore, It has been working perfectly in Double NAT with all our devices.

Also, I'm getting 20-25 mbps faster speeds through my Airport Extreme in 5GGz than the Comcast modem. Almost 60 mbps through the Extreme.
 
I also just upgraded my Comcast modem w/ wifi. You can change the password. You need to go to http://10.0.0.1, log on w/ admin and password as your password. Then click on 'change password'. You can also change the name of the wifi network for the Comcast modem and it's password.

I use an Airport Extreme as well. I have it set up in Double NAT in order to create a working guest network. Other than the Double NAT warning which I just clicked ignore, It has been working perfectly in Double NAT with all our devices.

Also, I'm getting 20-25 mbps faster speeds through my Airport Extreme in 5GGz than the Comcast modem. Almost 60 mbps through the Extreme.
Click to expand...

I truly apologize but I do not understand what you are saying ... what I am trying to do is to get the COMCAST Gateway to SEE my Airport.

I could make the recognition happen, but I would have to string a CAT5/6 cable along the baseboard from one side of the room to the other.

Why doesn't the COMCAST Gateway/Modem not see the Airport Extreme?

Will I have to purchase a Airport Express and place it physically next to the COMCAST box and let the Express link to the Airport Extreme?

I am seeing post after post saying that the new COMCAST Gateway does not see the Airport Extreme ... concluding to give up.
 
My bad. I was answering the original post and the use of Comcast's initial password for all their modems and that he could in fact change it.

My Extreme is connected by LAN. I didn't even know that you could connect the Extreme wirelessly to a modem.
 
And after some quick searching it does not seem possible to connect your Airport Extreme wirelessly to your modem. The option, it appears, is to connect your Extreme to your modem using LAN and then using another Extreme or Express to connect to the Extreme wirelessly or vice versa as you stated in your post.
 
Accessing http://10.0.0.1, I see my iMac's IP Address and the Mac Address.

Potentially "stupid" question now follows:

If the Comcast Gateway sees the Mac wirelessly, why can't the Comcast Gateway see the the Airport Extreme and then the Airport Extreme sees the iMac?

If the Comcast were a JUST a Modem, then a CAT6 cable would connect it to the Airport, allowing the Modem to "see" the Airport over the LAN.

Okay, change the Comcast to a wireless Gateway ... if it is wireless, the cable should no longer be required. This wireless Gateway sees the iMac. So in theory why can't the Comcast wireless Gateway see the Airport? The Comcast wireless Gateway does not need to see the iMac, just the Airport. And, in sequence, the Airport see the iMac wirelessly.
 
johnlove said:
Accessing http://10.0.0.1, I see my iMac's IP Address and the Mac Address.

Potentially "stupid" question now follows:

If the Comcast Gateway sees the Mac wirelessly, why can't the Comcast Gateway see the the Airport Extreme and then the Airport Extreme sees the iMac?

If the Comcast were a JUST a Modem, then a CAT6 cable would connect it to the Airport, allowing the Modem to "see" the Airport over the LAN.

Okay, change the Comcast to a wireless Gateway ... if it is wireless, the cable should no longer be required. This wireless Gateway sees the iMac. So in theory why can't the Comcast wireless Gateway see the Airport? The Comcast wireless Gateway does not need to see the iMac, just the Airport. And, in sequence, the Airport see the iMac wirelessly.
Click to expand...

I suspect the Comcast modem/router does not support WDS, and that is why it won't work to extend wireless like you described.
 
So after waiting for Xfinity to pick up the phone (they didn't), I decided to just put the AE into bridge mode, rather than the modem. That works fine, and now I don't need to change all my default networks, which is good.

But the modem is still broadcasting it's own network. I am probably just revealing my ignorance here, but is there a way to turn off that network? I logged into the admin panel for the modem, but didn't see anything. Is that even possible? Would it break the AE's bridge mode? Am I getting slower speeds from the AE by using it this way than if I were doing something else? Can I set the AE to be only 5 GHZ, or will that not work, since the modem is only 2.4 GHZ? They're connected via ethernet cable, so that shouldn't matter, should it?

Related: Xfinity is the worst. This new modem is so needlessly large.
 
Last edited:
williamsonrg said:
So after waiting for Xfinity to pick up the phone (they didn't), I decided to just put the AE into bridge mode, rather than the modem. That works fine, and now I don't need to change all my default networks, which is good.

But the modem is still broadcasting it's own network. I am probably just revealing my ignorance here, but is there a way to turn off that network? I logged into the admin panel for the modem, but didn't see anything. Is that even possible? Would it break the AE's bridge mode? Am I getting slower speeds from the AE by using it this way than if I were doing something else? Can I set the AE to be only 5 GHZ, or will that not work, since the modem is only 2.4 GHZ? They're connected via ethernet cable, so that shouldn't matter, should it?

Related: Xfinity is the worst. This new modem is so needlessly large.
Click to expand...

From looking over the Comcast support forums, it appears you cannot change the modem settings yourself, that Comcast has to do it from their end. However, they can both put it in bridge mode and also turn off the wifi. Forum members said they got results contacting support through a PM on their Twitter account.

The wifi on the modem has nothing to do with your wifi on the Extreme. You can configure your wifi however you want without regard for the cable modem wifi. You would ideally want the modem in bridge mode with the wifi off then your Extreme would handle DHCP and all wifi.
 
williamsonrg said:
I decided to just put the AE into bridge mode, rather than the modem. That works fine, and now I don't need to change all my default networks, which is good.

Can I set the AE to be only 5 GHZ, or will that not work, since the modem is only 2.4 GHZ? They're connected via ethernet cable, so that shouldn't matter, should it?
Click to expand...


You can add as many wireless access points as you like without speed penalty. It is farley common her to have multiple wireless networks feeding one modem. Your AE in bridge mode is an access point. The AE is suppose to pick an unused channel to avoid interference, but you can set that if need be. Multiple routers (those with DHCP on) can be trouble.

I typically run two or three wireless networks, one for wireless gaming and another for wireless streaming, one set up for guests, another for a few obsolete wireless devices that work just fine but are no longer supported by the AE.
 
Alrescha said:
In my experience, the magic word with Comcast is "Bridge Mode".
(and it works - I even got my old IP address back)

A.
Click to expand...

Agreed. I went through several rounds of nonsense with a chat agent and ended up back where I started. they kept trying to sell me a new modem.

I closed out and went back in, using the phrase "bridge mode" and it was done in seconds. You also need to tell them to turn broadcast off, to get them to kill the radio. If the wifi light is off, you're good.
 
I agree w/ Jeffe's MacAir: My Time Warner router + my Airport Extreme caused me to get the double NAT message. I clicked Ignore and all has been well since then.

On another note--if Weaselboy says it, take it to the bank!
 
OK. So my internet crapped out and Comcast had to come back and swap out the modem. The tech got wifi turned off and insists that the modem is in bridge mode, but...If I put the AEBS in DHCP and NAT mode, my network functions but I get a Double NAT conflict and a Conflicting DHCP Range error, all of which suggests to me that the modem is still trying to run my network.

If I switch the AEBS to bridge mode, it clears the errors but nothing can connect via wifi. Any help would be appreciated.


NVM: Comcast tech had connected the modem to the AEBS as both a modem and a client, hence the conflicts. Removed the offending connection and got a tech on chat to confirm the modem in bridge mode. All working properly now.
 
Last edited:
rayward said:
OK. So my internet crapped out and Comcast had to come back and swap out the modem. The tech got wifi turned off and insists that the modem is in bridge mode, but...If I put the AEBS in DHCP and NAT mode, my network functions but I get a Double NAT conflict and a Conflicting DHCP Range error, all of which suggests to me that the modem is still trying to run my network.

If I switch the AEBS to bridge mode, it clears the errors but nothing can connect via wifi. Any help would be appreciated.


NVM: Comcast tech had connected the modem to the AEBS as both a modem and a client, hence the conflicts. Removed the offending connection and got a tech on chat to confirm the modem in bridge mode. All working properly now.
Click to expand...

Make sure Comcast doesn't bill you for a "support call" for their stupidity.
 
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