IP conflict issue just with Macbook pro [2020] and Macbook Air [2012]


  • Every so often the MacBook on the network will show an IP conflict issue.

    I thought it might be something WIFI but this also happened on ethernet. Rebooting the Router seems to help and sometimes it will be hours before it happens again. Doesn't happens on any of the windows/android devices that use the network.

    I did try having a 5ghz SSID just for the macs which worked for a little bit but then it did eventually show a conflict and this still showed when connected directly by ethernet to the router.

    Software Version 3.4.3

    I have UPnP enabled

    Hardware NAT disabled

    The connection is DHCP through to a Draytek modem.

    Have tried lots of things but nothing seems to work. Any helps greatly appreciated!


  • It sounds like you probably have both the MacBook Pro and the MacBook Air configured with a manual IP address that's the same on both computers. You should go to...

    System Preferences -> Network -> Advanced... -> TCP/IP

    ... on both machines and you'll probably see that they are set to either "Manually" or "Using DHCP with manual address" and the same IP address on each machine. If that's the case, you'll need to either change it to "Using DHCP", so they are assigned different IP addresses by the router, or assign them manual IP addresses that are different and something that any other devices are not already using.


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