My Mac won't connect with Ethernet but will to wireless I apologize if this is a stupid question, but I'm not very tech-savvy. Using a iMac (21.5-inch, Mid 2010), running El Capitan version 10.11.6. Router is Amped Wireless ATHENA, High Power AC2600 Wi-Fi Router with MU-MIMO (RTA2600).

I have a Mac computer that is hardwired for Internet (I have a cable plugged into back of computer). My husband also has a computer hardwired, which is not a Mac. We also have wireless service. 

Earlier we had to reboot the modem and router.  Now, my husband's computer will work with Ethernet, but mine will not. I can only get connectivity with my Mac via wireless (192.168.X.XXX). I've checked network settings and it says Ethernet is connected but cannot connect to the Internet. 

Why not? It is setup as DHCP. I have no clue what to do.  Again, none of this happened until we rebooted/reset the router and modem.  

Any help would be greatly appreciated!

I did do a "renew" as suggested and the IP address came back as 169.254.xxx.xxx. I also noticed the "router" field is blank. Subnet mask is populated.
the IP address came back as 169.254.122.206.


The 169.254.xxx.xxx address is a "self assigned address."  It gets this address because it didn't get a DHCP lease from the DHCP server.  This could be due to either of the following:


No connection between your iMac and the router/switch
DHCP server is down


Check your cabling from the back of the iMac all the way to the router.  Make sure everything is plugged in properly.  If you look at your Network Settings, it should be "green" and say "connected".  



If it's yellow, that means it's plugged into a switch (getting power), but not communicating with anything.  Check the settings on your router to be certain that the DHCP server is up and running.