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spw70

macrumors newbie
Original poster
Jan 17, 2011
1
0
Desperately need help. All of a sudden, my wireless system shut down. I cannot log on using airport because I get an error messages saying my IP address is being used by another computer on the network. I use a Verizon DSL modem into the airport extreme to work my network. I have two Macbook Pros and an iMac desktop. We also have a couple of ipods and wireless Directv. I had no problems for a couple years and all of a sudden, my network is shut down. I turn everything off except the iMac and still the error message. I have tried inputting manual IP addresses on my imac and turning off both laptops. Every time I put a new address in on any of the computers and try to apply it, an error message comes up and says another computer is using that address. This SUCKS! Please help!
 
Does that DSL modem also do DHCP? If it does then you might be have Double NAT (Network Address Translation).

NAT would not be causing this. Double NAT can cause some connectivity issues to various services, but would not produce this type of error, especially with consumer grade equipment.

OP, have you restarted the modem and then the router? If no other device is reporting an error, it might be something is wrong with the machine, not the network.
 
NAT would not be causing this. Double NAT can cause some connectivity issues to various services, but would not produce this type of error, especially with consumer grade equipment.

OP, have you restarted the modem and then the router? If no other device is reporting an error, it might be something is wrong with the machine, not the network.

If he using the same subnet as the subnet the DSL modem/router is using, hence the same IP warning.
 
If he using the same subnet as the subnet the DSL modem/router is using, hence the same IP warning.

You still wouldn't get an IP warning and the connection wouldn't suddenly quit either for just one machine.

A duplicate IP is caused by one IP advertised by two or more different MAC addresses. Since the two segments are in different broadcast domains, the only device that would see this conflict is the router, not the Mac. Still, this isn't even related to double NAT, so I'm confused where that point comes in.
 
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