Since a few days I am encountering very strange Wi-Fi/Mac problems. I already Googled (but it is kinda hard to describe and search) therefor I try to explain the problem as good as I can.

I am owning some Apple products - this includes my iMac (2012), MacBook Air (2013), iPhone SE and Apple TV (2013). All of them are well connected to my WiFi. Now, As soon as I am booting my Imac and activating the Wi-Fi, I am no longer able to connect to any other website with my other devices. It simply doesn't work and times out - but as soon as I deactivate my Wi-Fi on my Imac, it works immediately and properly. More strange, If I deactivate and quickly activate the Wi-Fi on my other devices, it works for aprox. 10 seconds until I am no longer able to connect to a website again. Wi-Fi signal and connection is still available and connected on all my other devices. My router settings are also telling me that everything is alright and online. I really don't know if this is an internet provider problem or an Apple device one. I am owning a good bandwidth connection.

Other notable information:

  • Every device is up to date
  • Already restartet and reconfigured my router
  • About 3 months ago I completely re-setup my Apple devices
  • Already tried some different frequencies and Wi-Fi channels but didn't gave me anything
  • I am using the o2 Homebox 6641https://static2.o9.de/blob/13175994/v=3/Binary/kurzanleitung-o2-homebox-6641-englisch-download.pdf
  • The router configuration for LAN tells me that I am using a DHCP Server (DHCPv4), DHCPv6 Server is set to stateless for WiFI see settings in the picture below (sorry it's German language).

  • I don't have the "internet sharing" option activated

  • What is the model of router you are using? Is there a NAT or Dual NAT situation? If so, is the NAT on the router or the modem? Is there a DCHP service running on both your router and your modem? Please add to the question. Seems to be a NAT or DCHP issue on your router.— From review – bret7600 Jan 12 '18 at 18:32
  • Seems like a DHCP problem to me as well: are you sure you don't have the "internet sharing" option active in the "sharing" panel of the "system preferences"? – Gio Valerio Jan 12 '18 at 20:56

You must log in to answer this question.

Browse other questions tagged .