Mac Pro 2013 (6,1) -- using both ethernet ports?

[Iatros55]

I have a Mac Pro 2013 (6,1) that I used to replace my old iMac when it failed. I love the 'trash can' Mac Pro because it works so well for what I need (photo apps, cataloguing, programming). Due to my rural location, my internet has been via HughesNet and while satisfactory, there are data limits and long response times. Just recently, my telco has offered me cable DSL and I took their introductory offer. The DSL works well and seems to be as fast as my HughesNet, plus there are no data limits. It occurred to me to try using one Ethernet port for the DSL and the other Ethernet port for the satellite. It does not seem to work. The Internet Preferences window shows only the service plugged into the first Ethernet port. I can't seem to bring up the Ethernet 2 port at all. I had hoped to be able to switch from one to the other, depending on my needs.
Is anyone doing this successfully? If so, could I get an idea of how to accomplish this?

[I am running macOS Catalina 10.15.4 on my Mac Pro 6,1 with 64 gb of RAM, 1 GB SSD, and multiple ext HDDs using the USB3 ports.]

 

[Taz Mangus]

Is the second Ethernet port showing up under System Preferences->Network? If not try adding it. Maybe this article which might help: https://www.macobserver.com/tmo/article/how-and-when-to-use-both-ethernet-ports-on-a-mac-pro

 

[Iatros55]

Thank you Taz for this info. However the first problem to solve is that only one Ethernet port shows up on my network config window. It is always Ethernet #1, unless I leave the #1 port empty and reboot with one of my connections to #2 first. Both ports just don't show at the same time. Any ideas?

 

[DeltaMac]

In the network configuration window, click the (+) to add a port.
Click the Interface dropdown.
Does the #2 ethernet port show up in the list as a port that you can add?

 

[Iatros55]

Oh, man! I totally had forgotten how to add ports in macOSX. I did just that a moment ago; it was so easy that I am embarrassed to admit it. Now I see both Ethernet 1 and Ethernet 2 and the autoconfig is correct. Thank you all for your help.

 

[Taz Mangus]

Oh, man! I totally had forgotten how to add ports in macOSX. I did just that a moment ago; it was so easy that I am embarrassed to admit it. Now I see both Ethernet 1 and Ethernet 2 and the autoconfig is correct. Thank you all for your help.

Make sure to set the service order as that will decide which order the Ethernet ports will be used.