I have a new 64gb apple tv. It easily connects to my wireless network. (centurylong prism). However it locks an ip address and prevents one of my iMacs from connecting to the network unless I shut the power down on my apple tv. My apple airport used as a wireless link on my Yamaha Disklavier does the same thing when its powered on. Any suggestions of how to prevent this?
iPad 2, iOS 6.1.4
Contact your ISP
What device on your network is responsible for handing out IP addresses? If various devices sleep and then try to use their last known IP address when they wake you can get this sort of clash. In some cases you may want to fix the address for each device in your router or whatever is acting as the DHCP server.
tt2
I not sure if you resolved this? There could be many explanations. But I have observed and recorded some behavior with AppleTV Gen 4, which while the symptoms are a little different to yours, could be related to the same thing. I have observed the Apple TV gen 4 sending packets (gratuitous ARPs for addresses it does not own) which could result in other devices see the AppleTV taking control of IP addresses which it does not own. If your AppleTV is doing a similar thing for your iMac IP address, this could definitely cause the symptoms you are seeing.
I have documented this at :-
https://discussions.apple.com/thread/7455927
It is likely that the issue is caused by a very specific combination of things (rather than just 1 trigger), which means it is likely a lot of people will not be affected. But it is also likely that different combinations of things could trigger the issue. In my case I believe it is triggered by combination of Gen 4 Appl3e TV + other AppleTV + Enterprise Cisco Wireless which guards against potentially dangerous network packets. But due to the nature of the Gen 4 AppleTV gratuitous ARP, it is quite likely this could cause issues in all sorts of different environments.
I will continue to chase a solution on that thread.
my apple tv locks my wireless network ip address. I have to remove it from power to release the ip address
