[mkerr64]

Hi there

Ever since i upgraded to Mountain Lion i keep getting this error "Another device on the network is using your computer IP address"
The way i solve this issue to to disconnect and connect Apple Extreme network, which is a temporary solution and i do this every 2 days.
Can someone please tell me how i can avoid getting this error?

Thank you

[Don Pickett]

I've seen that error for a while: I have three machines and one iPhone all on the same network, all served by DCHP. So, if one machine gets powered down, and the DHCP lease expires, another machine may get that IP address. WhenI power the machine up, I get that warning.

Don't worry about it: your Airport Extreme will simply resolve the conflict by assigning new IP addresses. The only problem you would see is if you have one machine which needs ports forwarded from your router. If the IP address changes, you may have to change the port forwarding.

[mkerr64]

its just annoying that the only thing i can do to fix the problem is to unplug and plug in airport. this happens all the time when my Mac Pro is put to sleep

[Don Pickett]

Originally Posted by mkerr64 

its just annoying that the only thing i can do to fix the problem is to unplug and plug in airport. this happens all the time when my Mac Pro is put to sleep

There's no problem: the router should just reassign the IP address. Unless it's causing you connectivity problems it's nuisance message.

You may be able to increase the time of the DHCP lease, or something to that effect.

[Waragainstsleep]

Yeah, normally you can just click ok and it should all work fine.

You might be able to assign IP address by MAC address depending what is issuing your DHCP. That would stop it.

[EOSLightbox]

I have the exact same problem as the threadstarter and I understand how it feels => I know clicking the OK button to the message EVERY SINGLE TIME is all it takes to continue but it's just plain irritating!

Some background
===============
I just bought a Retina MacBook (I will call it rMBP for short) and when it arrived, it had Lion on it. So I migrated from my previous MacBook Pro to the rMBP using my TimeMachine backup before upgrading to Mountain Lion via the AppStore. A few days into using the new machine, I discovered a scratch on the left palmrest area - surprised (MacBook Pros are really difficult to scratch!!!) and kinda disappointed, I decided to call Apple Store (I bought it online). I was very happy that they decided to replace it with a new piece and really impressed that they decided to :
- send me a replacement
- let me try it and verify that all was ok before calling me back 2 days later to confirm and arrange for a pickup

Anyway, so this time round I migrated from the 1st rMBP to the replacement but this time using the TImeMachine backup that was synced to the 1st rMBP. Thats where my problems with this "Another machine... yada yada" message started. It never did complain on the 1st rMBP even though it was left on overnight but this one (the replacement) does.

Also, I have tried to remove both the wifi device and wifi profile before readding and although it seemed to work for a day, the problem came back on the 2nd day. My network config (Apple Airport Extreme in the bedroom and Asus RT-N66U in the living room running the DHCP) in the home was never changed throughout all this. Btw, no new devices other than these 2 rMBP have been added to the home network recently.
===============

So.... any suggestions (I will also be looking at changing the DHCP lease time but I was hoping that there is a fix to be done on the rMBP rather than a workaround)?

[mkerr64]

exactly, im also looking for a permanent solution as oppose to running into these error messages. hopefully in apple's next update they will resolve this issue.

[Don Pickett]

Assign static IP addresses, or increase the time of your DHCP leases.