Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

IP Configuration issue with Airport Extreme

When configuring my Airport Extreme to use the AT&T DSL internet connection, an IP Configuration conflict is reported. My IP address is shown as in use by the Ethernet ID - DHCP Server. As a consequence, the Airport is not reporting an IP address to allow an internet connection. Here is the actual message:


192.168.1.64 in use by d8:a2:5e:7a:6e:35, DHCP Server 192.168.1.254


Hard re-starting the AIrport Extreme does not shake this configuration error.


I am now connecting successfully to the internet with an ethernet connection to the AT&T modem.


Thanks.

MacBook (13-inch Early 2008), Mac OS X (10.5.7)

Posted on Jul 5, 2012 10:35 AM

Reply
15 replies

Jul 5, 2012 10:52 AM in response to Larry Whitney

Thanks.


AT&T has for many years specified that the modem needs to be configured in Bridge Mode when it is used with a non-AT&T router.


1) Setup the modem in Bridge Mode


2) Setup the AirPort Extreme to Connect Using = PPPoE and enter your AT&T user name and password so that the AirPort Extreme will store the information needed to connect.


http://www.att.com/esupport/article.jsp?sid=KB401764&cv=801,902&title=Connecting +a+non-AT%26T+provided+router+to+your+AT%26T+Internet+connection#fbid=43oi_bcpYy U

Jul 5, 2012 11:12 AM in response to Larry Whitney

this is typically an issue with another computer, in this case an Apple device d8:a2:5e:7a:6e:35, configured with ipaddress 192.168.1.64 either manually or one misbehaving.


One can look up Ethernet mac devices by searching for the first three octets d8:a2:5e, up at the following ieee networking folks site.


http://standards.ieee.org/develop/regauth/oui/oui.txt



So go thru all of your apple devices and look for the one with that mac address d8:a2:5e:7a:6e:35 and either reconfig to another address manually to one not in use, or set it up to use dhcp.


to check goto the apple on the top ;eft of the screen and select About the Mac, then click more info, then click Network, then select the ethernet entries in the active services section and it will report in the bottom section the check for the one that has mac address in question d8:a2:5e:7a:6e:35.


Hope this helps

Jul 5, 2012 2:20 PM in response to magnatar

Thanks for the link. Confirmed as an Apple item, from the first set of number pairs.


When I configured another Apple Airport Express - signal repeater for expanding the network, the same IP address configuration error message arrived showing this new device ID: 40:3C:FC:03:CA:91.


Using the System Profiler to look into Network Locations, as described to locate the hardware with these specific Ethernet ID's....... I locate the Airport Routers. These are the items I'm trying to configure, and they are the items coming forward with the IP error conflict.


PPOe isn't working. A DHCP - Bridge Mode set up provides a Green Light in every respect, just not a working IP address.

Jul 5, 2012 2:39 PM in response to Larry Whitney

Check out this thread for some interesting items. The same instructions work for several users...but not another.


Re: AirPort Extreme Set Up Issue



AT&T wants this modem and router to work using DHCP - Bridge mode.

Not sure what you mean here.


This modem will not work correctly with an AirPort Extreme unless you put the modem in Bridge Mode or PPP is on the Router and then configure the AirPort Extreme to provide the PPPoE service.


I pulled out my old 2210 to test and confirm. Everything works just fine the way that AT&T recommends.


I think you will have nothing but headaches if you try to configure the modem for PPP is on the modem. Even if you can get the DHCP issues ironed out, a Double NAT error remains.

Jul 5, 2012 3:30 PM in response to Bob Timmons

I agree with with Bob's remarks...


regarding DHCP, seems both AT&T and AP Extreme are assigning DHCP addresses and configured to start with the same ip address 192.168.1.64.


It odd the IP addresses they start handing addresses out at is the .64 address, thats not default for either AT&T or Apple I think. They usually start one address after the router or default gateway address which is usually 198.168.1.1


Are any wireless devices working, I would think not, but need to ask.


Make sure DHCP on the AP Extreme is turned off and in bridge mode and try again it that hasnt been done.

Jul 5, 2012 3:40 PM in response to magnatar

Make sure DHCP on the AP Extreme is turned off and in bridge mode and try again it that hasnt been done.

I'm afraid that we have confusion here.


My contention is that the correct way to configure things is to place the modem in Bridge Mode and have the AirPort Extreme provide DHCP and NAT services.


That is the way that it works for me....and the way that AT&T advises.


The modem will not act as a DHCP server for the network. If you place the AirPort Extreme in Bridge Mode, only one device will be able to connect to the Internet since the modem can only deliver one IP address.

Jul 5, 2012 5:07 PM in response to Bob Timmons

Bob, thank you for your contributions.


I discovered a Manually assigned IP address tab in the laptop, that was confusing this network. This was placed into automatic.


Additionally, the final configuration that is all GREEN LIGHTS and an internet connection, is showing the ETHERNET connection of the Airport Extreme to the ATT modem. The Airport is set to share a Public IP address, and the IPv4 is Using DHCP.

IP Configuration issue with Airport Extreme

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.