[X4U] Airport Express/iMac/iPad network issues

[Jeff Carruthers]

On Oct 12, 2010, at 5:38 PM, Paul Moortgat wrote:

> Hi Andrew,
> 
> I need to select the Airport option in Network if I want to use Wifi on the iPad.  It used to work until a few days ago.  It's an iPad 3G+Wifi.
> The Airport Extreme is a card inside the iMac.  Unfortunately I can't send screen dumps to this group.  I can send them to you off line.
> I also use DHCP but the address starts with 169....  Renew doesn't help.
> 1) Where do I find the airport's WAN?
> 2) The airport's LAN is 00:1c:c2:a4:40:09  (or is this wrong?)
> 3) Yes
> 4) Yes
> 
> Paul Moortgat
> 
> On 12 Oct 2010, at 20:50, Andrew Lynch wrote:
> 
>> Hi Paul,
>>  I'm a little confused by this statement:
>> 
>> "I got for a few days now a "Self-assigned IP address" message when I select the Airport Extreme in our iMac to use it to connect the iPad 3G."
>> 
>> My ipad connects directly to the airport extreme, without interaction with my iMac.  Can you perhaps rephrase your statement?
>> 
>> Are you setting the LAN address of the airport to 192.168.0.1, or the WAN address?  You probably need to leave the WAN address alone, that address should come from your internet provider.
>> 
>> I don't have my setup in front of me, but, in a nutshell, My internet service provider (ISP) uses DHCP to provide a WAN address to my airport extreme.  My airport extreme in turn uses DHCP to provide LAN addresses to the devices inside my network.  Each device is set to use DHCP to get an ip address.
>> 
>> So, try to answer these questions:
>> 1) Where does your airport get it's WAN (outside address)?
>> 2) What is your airport's LAN (inside) address?
>> 3) Is your airport extreme set to provide DHCP addresses to the devices inside your network?
>> 3) Are your inside devices set to use DHCP to get addresses?
>> 
>> Clue: LAN addresses usually start with 192.168. or 10.0.
>> Clue2: The airport extreme has a WAN address and a LAN address. It's LAN address is usually 192.168.0.1 or 10.0.0.1.  The WAN address is assigned by your ISP.
>> Clue3: Two devices on the same network cannot have the same address.  For example, if your Airport Extreme's LAN address is 192.168.0.1, your ipad and imac should use 192.168.0.2 and 192.168.0.3 (or some other address on the same 192.168.0. subnet).
>> 
>> Clear as mud I'm sure......
>> 
>> Good Luck,
>>  Drew


Paul: how is your iMac connecting to the Internet?

The most likely problem is that you don't have an active connection to the internet, either because of a problem with your ISP, your router, the modem your router is connected to (for cable or DSL) or the ethernet cable.

Also, there may be some confusion about terminology. The iMac's internal wifi card is called an Airport Express, but there's a mini-Airport basestation that goes by the same name and is an external device that plugs into the wall and connects to a router. I'm assuming you are not using the external airport express.

Jeff
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