disconnect the other Ethernet devices, power cycle the modem, router, and PC. Then retest. if all is okay, add the other Ethernet devices one at a time, power cycle each time. Also check your cables as you may have a bad one.

@ArcherC8 

Let me add this test description from yesterday for your additional consideration.  I isolated a test between cable modem, A7, and my laptop a did the following.  #1 power off devices and disconnect all ethernet cables, #2 re-connect all ethernet cables, #3 power cycle and boot up the cable modem (green status light OKAY as documented by Motorola and Comcast), #4 turn on power to A7 (green status light OKAY as documented by TP-Link Guides), #4 one-by-one I connected (directly) my laptop by CAT5E to each of the A7 LAN ports and ran Ookla speed tests. Each A7 LAN port test resulted in speeds of about 25/6... fairly consistent.  At the same time the WiFi (via my mobile phone) was getting about 80/6 on the Ookla phone app.  So, I have eliminated much of my house network and cabling concerns yet there is some sort of throttling at the A7 LAN ports.  But before  this test described above, a totally separate test scenario (using my house wiring) I did notice the D-Link Gigabit Switch on my LAN #3 was "pulling" perhaps forcing the A7 to send higher bandwidth downstream from the connected LAN port to the D-Link.  This downstream LAN speed test several rooms away resulted in about 85/6. Thoughts?  Maybe the A7 LAN port simply does not "push" the maximum speed unless "pulled"  on demand??  You will notice that my upload speed is never impacted in any of my tests.  

@Bogey_Golfer 

 

my ethernet is being throttled also. I have 600mbps/25 comcast.  I get full speed directly connected to the modem to my computer.  I get 265/10 connected through the A7 via ethernet. only ethernet plugged in.  wasted many hours.  im using comcasts 6 year old router/cable modem and getting full speed 650+/25.  Wasted all week on this router. Nothing fixes it. Sad.  set at full duplex.  qos off. nat boost off. tried everything

@MattmanTN 

Thanks for the validation that my situation is not unique.   TP-Link should fix this and have all LAN ports offer as much speed as their WiFi offers out of the box without playing games.  I was frustrated yesterday as well. In the next day or so, when home network is not critically needed by the family (COVID-19 stay at home remote college learning is happening at our house - at least the kids are using the A7 WiFi that works), I will add a Linksys Gigabit switch (yes, I have equipment laying around) on a second LAN port to see if two LANs with downstream Gigabit switches can "pull" maximum bandwidth offered by Comcast at the same time.  If yes, then that tells all of us something.  However, if it does work then TP-Link needs to be more tranparent on how their Gigabit LAN ports work out of the box.  There are no obvious configurations for me to set or change on the A7.  I mean their compeition (Linksys) does not make me jump throught all of these tests.  Maybe TP-Link should advertize "Gigabit Compatable".  Then the average consumer will as what the "h... " does that mean?

@Bogey_Golfer 

 

My guess it is some sort of bug/firmware issue.  but I did restore and try different firmware versions with no improved results.  Too bad it doesnt just work correctly out of the box lol

@MattmanTN @All 

Success!  But then again, I shouldn't have to do this!!  Here's the summary.  I ran a test this afternoon on A7 LAN #1.  Connected LAN #1 through my home wiring to my studio/office and connected to a Linksys Gigabit Switch (SE2800). Powered up the SE2800 prior to connecting the Ethernet cable .  Ethernet cabled a laptop to the SE2800 (WiFi OFF on my laptop).  Immeidately got my Comcast subcribed speed 75/5 (actually faster on multiple tests getting around 87/6). I walked over to my basement home office where the D-Link Gigabit switch was working on A7 LAN #3 and ran speed tests and still got about 85-90/6.  So, it appears the a Gigabit Switch on any A7 LAN will force the A7 to provide maximum bandwidth on the givin LAN as if you were directly connected to the cable modem to the ISP.  Also, A7 Wi-Fi was consistently high bandwidth throughout the test (via my cell phone).  Next,  I plugged in an extra Linksys E1200 WiFi Router to the Linksys SE2800 switch as I needed to find out if four LAN ports on another router downstream of the A7 to would also provide the 75/5.  Well, the router was not passing any traffic. So, time to reset the E1200 while connected to the SE2800.  That did the trick.  Now the SE2800 was broadcasting Wi-Fi (although slower at about 50/6).  However, the E1200 LAN ports were providing about 85/6.  So, my eventual setup (this coming Saturday) network trace to my Asus All-in-One (for which I am typing now) will be:  (1) Comcast Xfinity Service (2) Motorola MB 7420 Cable Modem (3) A7 Router <LAN #1 or #2> (4) Linksys Gigabit Switch - SE 2800, (5) Linksys Router EA7300 <Any LAN #> (6) Asus All-in-One.    I seriously doubt TP-Link expect their customers to do as much as what I did.  Let me know what you think!

I think you did great. It took lot of time and effort to get it working. Most would have given up and gone out and get a Mesh system. Thanks for sharing.

@Bogey_Golfer 

 

Throughout your testing we're any of the features such as QoS, Parental Controls disabled while having NAT boost enabled?

@Tony 

I am working with the A7 out of the box. Only did the latest upgrade two days ago (Sunday) because the notification was in my face.   Just now I checked the A7 status with my Tether phone app and status on QoS is not enabled.  Parental Controls not enabled.  I cannot find NAT Boost status. Did not play around with that setting, nor can I find the setting interface.  So, I presume it is whatever is out of the box / after firmware upgrade (OFF ? ).  Maybe you at TP-Link (I assume) you can replicate my scenario on your test bench. Please make life easier for your customers. 

@Bogey_Golfer It's under System Tools, bottom menu item System Parameters.  Then scroll down.

Or you can go to QoS menu, and it'll have a short cut to NAT Boost.