As a troubleshooting measure you could pick up either a USB Ethernet adapter or a PCIe adapter (both are inexpensive). You can see a number of them here. This one in particular would work nicely. Then if the system connects you have both the LAN back and have proved that the problem is not the router, which I doubt anyway. The flashing yellow could mean a problem with the connection or a bad port.

You Network adapter is enabled in Network status?

Here :

Buying a new PCIe network card will not prove that the MB network port on your R11 is not functioning.

When I had network problems, back in the day before using DHCP I fixed many problems by unistalling everything related to the network port. Eliminate any windows configuration that may have been messed up, by Killer or whatever.

So, uninstall Killer software, delete network device from Device Manager, reboot.

Windows will detect and reinstall the device, if this works you can proceed to installing Killer software.

Ok

I think there is some misleading interpretation of your static orange and flashing yellow lights, on the computer port this is normal and means the port is communicating upstream at least.

On the Hub or router however, an amber led on the port means the network port of the computer connected is powered but sleeping, usually with WoL. 

Sorry, after reading my last response I realized it was not very clear. Device manager shows the network card, that it is enabled, and in working order. 

I was trying to say that I didn’t list this step in my original post as part of my troubleshooting procedures.

@jtylersimmons84 
For static IP address you should not do it in network configuration in windows, it is not easy to get it working.

Configure static adresses in the router, leave windows use DHCP to fetch it.

What does "failed to list it" mean?

Your card is not recognized in "Device Manager"?

For the past week I can only connect to the internet via WiFi. The Killer E3000 Ethernet port connection repeatedly shows unidentified network. Computer Ethernet port has solid orange light with flashing yellow.

Here is what I have tried:

1. updated BIOS and network card drivers. No change.

2. deleted/reinstalled network card, no change.

3. plugged same cable from router into a different computer. That computer connected no problem.

4. tried command prompt ipconfig release/renew. System released and renewed IP, but still not identifying network.

5. I tried setting a static ip/gateway for the system. Still same result.

6. tried Ethernet connection from modem instead of router, still no luck(connection from modem works on different systems).

7. called dell customer service,  Rep said it is a configuration issue with the router 

8. I think the Ethernet port went out, but can’t seem to convince customer service that’s the case. What else can I do to fix this. I’m willing to try anything at this point.

=====================

First, I think WiFi over-rides Wired (or vice-versa) , so if you want to use Wired-Ethernet ... be sure you are disconnected from WiFi SSID (hotspot).

Also, be sure Windows-10 is set to use "Private Network Profile".

1. Good

2. From Device Manager ? Also uninstalled any "Killer Networking" nonsense first? If so, Good.

3. Good. So, cable and Router are good. Still, I would try a brand new CAT-6 or CAT-7 cable directly to router.

4. Good and Correct. Sounds like you know a bit about this.

5. Fine to try but set back to Dynamic/Auto. Be sure Router still has available IP's in DHCP range. Reboot all networking (Modem, Router, Switches, etc.).

6. Yeah, that is tricky now-days since most ISPs only give you the one IP address. Everyone runs a Modem/Router or Residential Gateway now-days. You already tested this (item #3 above).

7. I think a rushed and Incorrect determination.

8. It might have. Often (not lately, but over the years) any time I see this level of strangeness (after this level of trouble-shooting) it's a bad ethernet card/circuit. However, I've seen some crazy networking problems caught during normal troubleshooting (which you have done most of). At one time or the other, I've see a example of every single hardware part in "the network chain" fail. Also, a good share of drivers/firmware/software/OS problems.

Someone mentioned trying a USB-dongle. Well, you tried the Internal WiFi and it worked (so that is basically the same test). Yeah, pop-in the new PCIe-NIC and see what happens. Might have to disable Internal NIC via BIOS or Device-Manager first.

Finally, I HAVE SEEN bad (Killer Networking) drivers cause some crazy/weird problems. But just that once and Aurora-R6 has been fine since.

https://www.dell.com/community/Alienware-General-Read-Only/Aurora-R6-Hard-Lockup-and-crash-while-gaming-SOLVED/m-p/5504138/highlight/true#M6114

I went ahead a bought a PCIe card since they were cheap. It should be here tomorrow, and I’ll update if that did it. I think I’m this is a good avenue to narrow down if it’s the card or something else.

Thank you for the response. I did check this (but failed to list it). I also ensured that the IPv4 settings were automatic, except for when I set the static IP/gateway.

Very true and I agree. But the adapter card will serve 2 purposes. First to give the user a LAN port that should work (assuming no other problems). And second to confirm that the router is not the source of the problem.

"It sounds to me like it's possibly not synchronizing properly with the network port of your router." 

I think he mentioned getting the same problem when the router was bypassed via direct to modem connection. 

Lots of good ideas here.  If all else fails (especially if you have a spare storage drive sitting around to troubleshoot with), you can try a clean win 10 install and connecting via ethernet, don't even set up wifi.  Generally you would expect ethernet to work with default drivers loaded (especially if it was working previously and no settings were changed on the router). Work up from there. 

Also, you don't have any sort of MAC filtering enabled from your service provider or on the router settings, right? 

this NIC can sink at 2.5G standard. It sounds to me like it's possibly not synchronizing properly with the network port of your router. If your router only has 1 gigabit capabilities, your NIC will have to connect at 1 gigabit up/down. I would try and force the NIC to connect at 1 gigabit instead of auto negotiate the connection

=======================

This is good.

Not lately, but I have seen this rarely. I forget if Link-LED still lights or not. I would try forcing to maybe 100.

I hope @jtylersimmons84  comes back ... lots of good ideas here.

@r72019 @Tesla1856 

He also said : plugged same cable from router into a different computer. That computer connected no problem.

The router is not the problem.

@Vanadiel has found a good idea, I remember once long ago having to force the properties of my 1Gbit port to be 100Mbit on my old 100Mbit switch.