[SOLVED] Netgear AC1750 not getting full speed over ethernet

Dealer of Aces

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Jun 23, 2014
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My ISP recently upgraded their network and now offer gigabit speeds. I upgraded yesterday and went to BestBuy and purchased a DOCSIS 3.1 modem (Link below). I already had a decent router that claimed it supported gigabit over ethernet so I wasn't concerned with it. When plugging directly into the modem I'm getting around 960/20 (1000/20 is my plan so this is more than sufficient). When the router is plugged into the modem the 2.4 ghz band is around 20-60 down and the 5 ghz band gets anywhere from 300-550 when in the same room. Wired directly into this router I get about the same as the 5 ghz band. I've factory reset, ensured QoS was still off, toggled beamforming on/off, and turned off several other settings such as traffic meter as suggested in other forums but can't seem to get it to past that mark. I had 1 speedtest that got about 800 wired but haven't been able to reproduce it and it immediately went away after the speed test completed. All of my devices are capable of gigabit speeds so I feel like theres something I'm missing.

Also, if I put a relatively cheap gigabit switch between the modem and the router I can get gigabit ethernet off the switch but my understanding is that you shouldn't* place those between the modem and the router (my knowledge of networking is relatively limited).

Any ideas? Also, include whatever information you'd like in as technical of a manner as you like. I'm always excited to learn more about tech and networking has been a weakness of mine.

I have ordered a nighthawk X6 AC 3200 in hopes that it (1) improves wifi coverage on our house and (2) may improve ethernet performance.


Note: I thought of this later but I occasionally stream my desktop from our game room downstairs over ethernet. Even though all of my equipment is new and the wires are cat7, nVidia shield TV shows random spikes of lag where it says my bandwidth is insufficient. Could my router be bad? I need to stick with netgear because I've already got the netgear nighthawk x6s mesh extender for full wifi coverage on our place.




Router
https://www.bestbuy.com/site/netgear-ac1750-dual-band-wi-fi-5-router-black/9054017.p?skuId=9054017

Modem
https://www.bestbuy.com/site/motorola-docsis-3-1-cable-modem/6105800.p?skuId=6105800

Router ive ordered but hope to not need because its pricey and I just bought a house soo.....
https://www.amazon.com/gp/product/B00KWHMR6G/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
 
Last edited:
Hold on the new router and switch. The switch may not even be needed. Even if so, its' presence should be transparent overall and not effect performance one way or another.

So your house is wired for ethernet - correct?

You mentioned Cat 7: is all of the wiring Cat 7 or are you just referring to the cables between devices and network wall ports?

Overall there is no way to know if a new router will make a difference. My primary reason for stating that is because the cause of the problem(s) has not been identified.

Wireless is inherently slower than wired. And performance can be even more reduced by surrounding environmental factors.

Not too mention network adapter related issues: drivers, configuration, etc..

Random spikes may be a result of a poor connection: maybe at the patch panel or inside an ethernet wall jack.

Could be poor workmanship (punchdowns), improper cable runs (kinks, bends, stapled down too hard), defective/deficient cables (copper clad aluminum).

Since you do like to read and learn, start by reading some tutorials about how to install a home network.

Then begin inspecting your home network. Draw/map it all out. Look at the cable runs, the patch panel, inside the wall outlets. Note all devices, cable specs, product branding etc..

Seeing and knowing the big picture is important. You may, for example, discover that a single loose (but not disconnected) punch down wire is the culprit.

Or that one of those "Cat 7" cables is not as it should be. And performance bottlenecks accordingly.
 
The wifi numbers are what is expected. They vendors like to tell lies about the speeds. Yours are what most people see close to the router. In most cases the end device is the limiting factor and not the router. Most end devices for example only have 2 antenna so they can not do stuff like 4x4 mimo.

There is no reason to put a switch between the modem and the router. Only 1 device is allowed to get a IP from the modem and that is your router. A switch provides no benefit when you can't plug anything else into it, you might as well use a simple cable.

You should be able to get 960m through that router. Not sure why it doesn't work It is not likely a cable issue since you would be limited to 100mbits. You have the right idea factory reset the router and only do basic configuration like passwords and wifi settings. To get very high speeds routers bypass the CPU to do the nat. Some feature..firewall, qos etc require traffic to go via the cpu.

If this still continues to be a problem try to use a tool like iperf to test between 2 machines in your house. This will show if you have issues with a pc or cable problems. You should get well over 900mbps between 2 devices in your house. Of course you want to run on ethernet. The traffic only passes through the switch/lan part of the router so the router should have no impact on this test.

If you get good speeds between the pc but still have issues to the internet I am unsure. That router is suppose to be able run at gbit speeds. If you really wanted you could test like the sites do and put a PC on the WAN side and then run IPERF between them. Kinda messy to setup and not sure what it would prove other than if the router can really pass the traffic.
 
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Hold on the new router and switch. The switch may not even be needed. Even if so, its' presence should be transparent overall and not effect performance one way or another.

So your house is wired for ethernet - correct?

You mentioned Cat 7: is all of the wiring Cat 7 or are you just referring to the cables between devices and network wall ports?

Overall there is no way to know if a new router will make a difference. My primary reason for stating that is because the cause of the problem(s) has not been identified.

Wireless is inherently slower than wired. And performance can be even more reduced by surrounding environmental factors.

Not too mention network adapter related issues: drivers, configuration, etc..

Random spikes may be a result of a poor connection: maybe at the patch panel or inside an ethernet wall jack.

Could be poor workmanship (punchdowns), improper cable runs (kinks, bends, stapled down too hard), defective/deficient cables (copper clad aluminum).

Since you do like to read and learn, start by reading some tutorials about how to install a home network.

Then begin inspecting your home network. Draw/map it all out. Look at the cable runs, the patch panel, inside the wall outlets. Note all devices, cable specs, product branding etc..

Seeing and knowing the big picture is important. You may, for example, discover that a single loose (but not disconnected) punch down wire is the culprit.

Or that one of those "Cat 7" cables is not as it should be. And performance bottlenecks accordingly.

Thanks for the reply! So to elaborate a bit. We just purchased this house at the end of January. The Wiring was done through the walls after it was built by the previous owners and is done with Cat 6a. I believe it was done for a security system. Currently, it is only being used to give wired connection to my desktop upstairs on the opposite end of the house. In order to remove those house wiring from the equation I use a 3 foot cat 7 cable from the modem to a computer and received full gigabit speed. So I believe the modem is functioning properly. Its when the modem is connected to the router and I'm hard wired into the router that my speed is cut in half. I understand that the wireless will not be as fast and I'm not concerned with it. All gaming or speed related tasks are done wired anyway. I will be replacing the current wiring with my own Cat 7 cable soon.

I was able to achieve 960 Mbps down using 2 different Cat 5e, a Cat 6a, and 2 different Cat 7 (3 foot and 200 foot) cable when plugged directly into the modem. All cables do the same on the router. I mentioned the wireless speed for 2 reasons: first, my 2.4 ghz network seems slower than when I first purchased the unit. Second, my wired through the router does not exceed the 5 ghz network speed by much or at all. I'm currently not using a switch in my network. The only reason I mentioned it is because I wanted to illustrate that the modem is putting out full gigabit internet it just seems as if the router does not.
 
Also, if I put a relatively cheap gigabit switch between the modem and the router I can get gigabit ethernet off the switch but my understanding is that you should place those between the modem and the router (my knowledge of networking is relatively limited).
That is generally incorrect.

The typical parts chain is:
modem->router->switch and other devices.

There are more convoluted configurations whereby a switch would be between the router and modem, but that is outside the scope of what you're trying to do.

As noted above: Identify the problem before applying a solution.
 
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That is generally incorrect.

The typical parts chain is:
modem->router->switch and other devices.

There are more convoluted configurations whereby a switch would be between the router and modem, but that is outside the scope of what you're trying to do.

As noted above: Identify the problem before applying a solution.

Thanks for the reply. I actually noticed when rereading your quoted text that I made a typo. I meant to say that my understanding is that you shouldn't* place those between the modem and the router. I spent a few hours messing with it yesterday to no avail so I wasn't sure my next steps.
 
The basic principles for connectivity go modem>router> switch
On the router the link light color indicates speed. White is for gigabit Ethernet. Do you see that color? Amber is slower connection.
Remember if you have a broad band circuit, you are sharing your connection with everyone so you only guaranteed UP TO gigabit speeds. During peek usage you will not see it.
 
Are you sure that only one device, modem or router, is providing DHCP IP addresses?

Normally that is turned off/disabled on the modem and enabled on only the router.

Yes. Only the router is providing DHCP addresses. I've double checked the modem and there aren't any settings that can be changed regarding it.


The basic principles for connectivity go modem>router> switch
On the router the link light color indicates speed. White is for gigabit Ethernet. Do you see that color? Amber is slower connection.
Remember if you have a broad band circuit, you are sharing your connection with everyone so you only guaranteed UP TO gigabit speeds. During peek usage you will not see it.

All lights are white. I understand that up to gigabit speeds is what im paying for. But when I get full gigabit (only person connected) direct from the modem then immediately plug the router into the modem and my pc into the router and those speeds are more than cut in half I get the feeling that something is wonky. I can immediately unplug the computer from the router nd back into the modem and I'm back up to gigabit speeds.
 
All lights are white. I understand that up to gigabit speeds is what im paying for. But when I get full gigabit (only person connected) direct from the modem then immediately plug the router into the modem and my pc into the router and those speeds are more than cut in half I get the feeling that something is wonky. I can immediately unplug the computer from the router nd back into the modem and I'm back up to gigabit speeds.
That's a good start on the troubleshooting chain.

Modem-> PC = ~full advertised speed
Modem->router->PC = major slowdown.

The indication would be either the router, or one of the connecting cables is at fault.
 
That's a good start on the troubleshooting chain.

Modem-> PC = ~full advertised speed
Modem->router->PC = major slowdown.

The indication would be either the router, or one of the connecting cables is at fault.

I'm thinking it might be the router. I've checked 5 different cables to be thorough: 2 Cat 5e, 1 Cat 6a and and 2 Cat 7 (varying lengths).

I'd make sure the firmware on the router is current and return it for a different model if the firmware update does not fix it.

Firmware is completely up to date. Can't return it because I purchased it in september of 2018. Until yesterday, my internet speed wasn't really high enough to saturate it. The 2.4 ghz band has always been a bit slower but only my wife uses it and I use the 5 ghz which has been more than sufficient.
Are you able to look at the IP addresses being used by all devices connected to the router when the router is being used?

There should not be any duplicate IP addresses.

I'll take another look but I don't think thats an issue since when I factory reset the router, I did not connect anything to the router before performing my second round of testing with the same results aside from the hardwired PC.
 
That's a good start on the troubleshooting chain.

Modem-> PC = ~full advertised speed
Modem->router->PC = major slowdown.

The indication would be either the router, or one of the connecting cables is at fault.

Also,
Modem -> network switch -> router -> PC major slowdown
------------------------- |
------------------------ V
------------------------PC -> full advertised speed

I test everything one at a time as to not interfere with other devices testing.
 
Contact Netgear. It's still under warranty.

Unfortunately netgears phone and live chat support runs out after 90 days. I think the only thing I can do is put in for hardware replacement? I'll try to get in touch and see what they say.
That or there's some sort of traffic scanning going on. Maybe mess around with the qos settings or put it into bridge mode for testing.
You should contact the vendor of your findings. They probably have a quick and easy solution.

I have disabled all of those settings including traffic meter.
 
Also,
Modem -> network switch -> router -> PC major slowdown
------------------------- |
------------------------ V
------------------------PC -> full advertised speed

I test everything one at a time as to not interfere with other devices testing.
There, the switch is merely a passthrough device. Unless actually faulty, it neither speeds up nor slows down the overall performance.
 
Thanks for all the advice everyone! I'll be doing some more troubleshooting tonight/tomorrow and will update this thread when I've figured something out. I'll mark the solution that is closest or leads me to the correct path.

Regards!
 
I need to go back a bit.

Verify:

ISP ----- coax-----> Motorola cable Modem ----- coax (?) -----> Netgear AC1750 [LAN] ------ethernet ----> PC and ~~~ wireless ~~~> wireless devices

Is the physical connection between the Motorola and the Netgear AC1750 coax or ethernet?

The Motorola having only one Ethernet port - correct? Which works at full speed/performance when the PC is directly connected if I am following correctly.....

If the connection is Ethernet, which LAN port is being used on the Netgear AC1750 to connect between the Motorola and Netgear devices?
 
I need to go back a bit.

Verify:

ISP ----- coax-----> Motorola cable Modem ----- coax (?) -----> Netgear AC1750 [LAN] ------ethernet ----> PC and ~~~ wireless ~~~> wireless devices

Is the physical connection between the Motorola and the Netgear AC1750 coax or ethernet?

The Motorola having only one Ethernet port - correct? Which works at full speed/performance when the PC is directly connected if I am following correctly.....

If the connection is Ethernet, which LAN port is being used on the Netgear AC1750 to connect between the Motorola and Netgear devices?
The netgear doesn't have coax and all the port information is in the manual. The wan port is what's used to connect the router to the modem.