Netgear D6400 VDSL modem // EE Gigabit broadband bottlenecks at 150 Mbps

[spawnsworth]

Hi all,

I've been using my trusty D6400 for a few years and recently upgraded my broadband to 900 Mbps with EE here in the UK.  For some reason the download speed bottlenecks at around 150 Mbps.

The EE Smart router does not have this issue.  I can get up near 900 Mbps without issue.  Is there a hardware limitation on the D6400?  I do not see any compatible 3rd party firmware for this model so guess I might be out of luck.

I am also using the latest firmware.  If there is no known way to resolve this, what is a good alternative to replace the D6400?

Thanks!

[plemans · Accepted solution]

•  did you factory reset/reinstall after updating your speeds? If not, try that. during the install, make sure to leave qos, access control, traffic monitoring, and parental controls all disabled. They can slow speeds
• are you using your modem/gateway from your ISP? many of them are modem/router combo devices and cause a double nat. 

A double nat happens when you cascade more than 1 router.
https://kb.netgear.com/30186/What-is-Double-NAT
Fixes? There’s 3 options but only use 1.
1. Put the modem/gateway in modem only/pass through mode. This disables its routing functions.
2. Leave the modem/gateway in router mode but put the Netgears IP address into its DMZ. This forwards the data to the netgear. You can either leave the modem/gateway’s wireless enabled or disabled. Just make sure its using a different wifi channel to prevent interference
3. Put the Netgear into access point mode. This disables its routing functions. Wifi/ethernet still works but it does disable some features.
https://kb.netgear.com/26765/Which-features-are-disabled-on-my-NETGEAR-router-when-it-is-set-to-AP-M...

[plemans · Accepted solution]

•  did you factory reset/reinstall after updating your speeds? If not, try that. during the install, make sure to leave qos, access control, traffic monitoring, and parental controls all disabled. They can slow speeds
• are you using your modem/gateway from your ISP? many of them are modem/router combo devices and cause a double nat. 

A double nat happens when you cascade more than 1 router.
https://kb.netgear.com/30186/What-is-Double-NAT
Fixes? There’s 3 options but only use 1.
1. Put the modem/gateway in modem only/pass through mode. This disables its routing functions.
2. Leave the modem/gateway in router mode but put the Netgears IP address into its DMZ. This forwards the data to the netgear. You can either leave the modem/gateway’s wireless enabled or disabled. Just make sure its using a different wifi channel to prevent interference
3. Put the Netgear into access point mode. This disables its routing functions. Wifi/ethernet still works but it does disable some features.
https://kb.netgear.com/26765/Which-features-are-disabled-on-my-NETGEAR-router-when-it-is-set-to-AP-M...

[michaelkenward]

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@spawnsworth wrote:

Hi all,

I've been using my trusty D6400 for a few years and recently upgraded my broadband to 900 Mbps with EE here in the UK.  For some reason the download speed bottlenecks at around 150 Mbps.

The D6400 is DSL a modem/router.

---

The EE Smart router does not have this issue.  I can get up near 900 Mbps without issue.  Is there a hardware limitation on the D6400?  I do not see any compatible 3rd party firmware for this model so guess I might be out of luck.

---

The people who write 3rd party firmware rarely address modem/routers.

As @plemans says, you are using two routers. Bad idea.

What do you want the D6400 to do that you cannot make happen with the EE Smart router? More wifi? For that think AP mode.

How do I change my NETGEAR router to AP mode? | Answer | NETGEAR Support

Then you face this:

Disabled Features on the Router when set to AP Mode | Answer | NETGEAR Support

So it is back to what you expect the D6400 to do.

[spawnsworth]

Hi guys thanks for the answers.
I should clarify that I am not using 2 routers. I'm well aware that's a bad idea. I connect to my EE service directly from the Netgear. I'll try a factory reset later.

[spawnsworth]

OK so it turns out I had completely forgotten that I enabled QOS (for PES 6 online).

The penny dropped as soon as I realised.  Instead of factory resetting, I disabled QOS and rebooted everything.

All is working great now and my upload speed is 100 MB and no longer capped at 51.  Strange that this is a known bug with EE's "smart" hub that has been around for a couple of years.  No longer a concern as that's me up and running on my D6400.

Thanks for the answers guys!