On our network of around 11 devices, there are 2-3 MacBooks that regularly state that their IP address has been taken and the device cannot connect to the internet. We switch off the wifi routers and the modem and this seems to solve the problem for a day or so. How can we stop this form happening? Is it a MacBook or an Airport problem?
MacBook Pro, OS X Yosemite (10.10.1)
We don't know what modem you have.
Can you provide the make and model number?
We don't know what WiFi routers you have.
Can you provide the make and model number of the routers?
How is the network set up? Starting with the modem, what connects to what?
Hello Bob; hope this clarifies;
1. Modem: Telstra 2701HGV-W (see images attached);
2. Wifi router: base station, Apple Extreme, connected to modem by cable.
3. Wifi router: Apple Express, connected to the Extreme base station over wifi to extend its range. Configured using the Airport Utility.
Are all of the devices using DHCP to acquire their IP address? Has anything been configured with a static IP?
There are several apps that can scan your network to show you all of the devices and their IP addresses, like LanScan on the Mac and Net Analyzer Lite for iOS (both free). That may help you to figure out what is going on.
Thanks for the information, this helps a great deal.
The Telstra 2701HGV is not really a modem in the traditional sense. It is a modem/router that combines the functions of a separate modem and separate router in one package. As such, the 2701 is in charge of all of the IP address assignments for all devices on your network.
Since you do not want two devices both trying to act as a router on the network, the AirPort Extreme needs to be configured in what is known as Bridge Mode to work correctly on the network. When the AirPort is in Bridge Mode, it follows the instructions that are provided by the 2701.
So, the first troubleshooting item here would be to confirm that the AirPort Extreme has been set up correctly to work with the 2701 on your network. To do that, open AirPort Utility on your Mac. It is located as follows: Finder > Applications > Utilities > AirPort Utility.
Click on the picture of the AirPort Extreme, then click Edit in the smaller window that appears. Then, click the Network tab at the top of the window. Look for the setting for Router Mode. It should read "Off (Bridge Mode)", similar to the illustration below. Is this the setting that you see when you run this check?
If not, change the setting for Router Mode to "Off (Bridge Mode)" as indicated and then click Update to save the new settings.
Report back on your findings.
Hi Bob. I've checked. Extreme is set correctly to "Off (Bridge Mode)".
OK, thanks for confirming that. This tells you that the AirPort Extreme is configured correctly and that it is acting as a pass through device to provide IP addresses to all of the clients on your network from the Telsta modem/router. In other words,the AirPort Extreme is not involved at all with issuing IP addresses on your network, it simply passes through the information that it receives from the Telstra device.
It is up to the DHCP Server in the Telstra modem/router to provide correct IP addresses for devices on the network, and based on your report, it is having some difficulty providing this service correctly.
Try a complete network power cycle to see if a fresh start will help the Telstra modem/router keep better track of devices on the network. To do that, power off all of the devices on the network.....everything, computers, mobile devices, printers, etc....in any order that you want.
Wait a minute, then power up the Telstra modem/router for a few minutes. Then, power up the next device connected to the Telstra device and let it run for a full minute. Keep starting devices one at a time the same way about a minute apart until the network is back up again.
If the Telstra modem/router is still having trouble with IP address assignments, it may likely be defective, and should be replaced.
If you want to continue to use the same Telstra device, then check with your provider to see if it might be possible to configure the Telstra to provide a fixed, static IP address for each network device. In other words, every device on your network will always receive the same fixed IP address time after time.
It is quite a bit of work to set this type of feature up, but it might help the Telstra keep things straight on the network.
ip address taken
