iMac Ethernet connection issue

  • I recently had to replace my AMPLIFI mesh router and now I cannot get the internet to work on my Mac as a wired connection. It works fine on wireless when I unplug the Ethernet cable. As I recall, when I installed the first router there were a few settings that needed to be changed in the Mac but I don’t recall the specifics. Maybe the dns settings?

    Can anyone offer some guidance to get my wired connection back up and running?

  • You have to have the wired ethernet service available in the network preferences. Not just wifi by itself.

  • @tony-st-clair-0

    Yes. It worked before with the old router and I think support had me verify a few settings

  • Have you set a static IP up on your Ethernet connection?

    If you go to System Preferences > Network > Ethernet can you check Configure IPv4 is set to DHCP? If so, there should be no issues from your Mac's side. If not, set it back to DHCP and see what happens.

    The Ethernet from the back of the Mac must go into the LAN port (Not blue WAN) on the AmpliFi Router (or into a network switch which is directly connected into the AmpliFi router).

    If the cable is "dodgy" or not properly connected, your ethernet on your Mac will be Red. If it's green but has an APIPA (169.254.x.x) IP address, then the Ethernet is not connected to the router, but is connected to a network device away from your DHCP server (AmpliFi Router)

    Hope this helps

  • Just wondering, did you get this fixed in the end, as I am having a very similar issue.

    Mac over wifi connects fine, but when using ethernet I get APIPA IP address.

    I have a Virgin (UK) cable modem in bridge mode

    Modem---> Amplifi (DHCP) ---> wired cable through house ---> TP Link Switch ---> wired cable ---> mac mini

    I'm convinced this is an issue at the mac end, I have other devices connected to the switch that get IP addresses

    I've tried static IPs, rebooting everything at various intervals. From the amplifi app it can see the mac but for some reason it doesn't give it the IP address.

    After wasting a morning, I'm back on wifi!

  • @pini-patel What versions of MacOS are you running by chance? Personally I have an iMac and Macbook Pro which run wired (Macbook Pro connected via an ethernet port on a Mac monitor) And neither of my devices are experiencing this issue. Currently running Mojave v10.14.6

  • @pini-patel As silly as this may sound try swapping the cable to the Mac - or verify that it works with another device in the exact same port on the switch, and - if possible - try the Mac wired directly into the AmpliFi with the same cable.

    If it works directly in the AmpliFi (with the same cable), then you might have a dodgy port on your switch - or, a random network "glitch".. Once I had a printer in a workplace connected to a Netgear switch and it just wouldn't work. As soon as we put the uplink from the netgear into a small 4port switch, and then plugged the printer into that it worked!

    If none of that works, try deleting the Network Adaptor in System Preferences > Network > minus button in bottom left window, and re-add with the plus.

  • @martin-adams said in iMac Ethernet connection issue:

    If it works directly in the AmpliFi (with the same cable), then you might have a dodgy port on your switch - or, a random network "glitch"..

    I actually had a bent pin in one of my iMac's ethernet ports. Worth taking a peek to see if that's the case (pretty easy to re-align with a needle.) Wasn't so much bent as stuck under a neighbouring pin.

    Also possible that the ethernet device is set to "Off"rather than Using DHCP.

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