Solved iPv6 issue, slow downloads

[tallytr]

With iPv6 enabled downloads are around 40% slower than with iPv4 only... why?
Measured on RT-AX86U router wired and connection to a Telus Fibre modem (NH20A) in 10G bridge mode on 1G internet plan.

Merlin: 3004.388.8_4

 

[dave14305]

The IPv6 speedtest server may be farther away than the IPv4 server, or the IPv6 server is overloaded. There’s really no way for us to tell you why. A lot can happen between the router and the destination.

Are the results consistent? Are you certain the tests are going to an IPv6 destination?

 

[tallytr]

The IPv6 speedtest server may be farther away than the IPv4 server, or the IPv6 server is overloaded. There’s really no way for us to tell you why. A lot can happen between the router and the destination.

Are the results consistent? Are you certain the tests are going to an IPv6 destination?

I have zero clue actually, all I know what I see on the router speed test page, are you saying do not worry, would you leave IPv6 enabled?

 

[dave14305]

I don’t mind IPv6. I always have it enabled. If the Speedtest results are not consistently poor, then it’s probably not related to IPv6 being enabled. A test run at 4PM might suffer compared to one run early in the morning. See if there’s a pattern. But don’t fret much about speed tests run on the router. Better to test from a wired client.

 

[tallytr]

...actually, I checked my PC Ethernet adapter settings and that was the issue, had Gigbit lite enabled...so nothing to do with ipV6.

Speedtest now on PC, never tested there before, only on router ;-)

 

[tallytr]

...also checked later on wired Apple TV Ookla Speetest App, there the result is ~ 940 Mbps up/down on my 1G plan so that is great.
Leaving IPv6 enabled on my RT-AX86U, it is supported by my ISP (TELUS), also in the bridged ONT/modem (NH20A) mode.

 

[Tech9]

Since we have IPv4 public addresses available in Canada IPv6 won't give any real advantages. You have to make sure you secure both IPv4 and IPv6 the same way. In case you run scripts - check which ones are IPv4 only. If case you run VPN - careful with common IPv6 leaks. In case you use QoS - verify up/down limits, IPv6 may break it. General advice - don't enable features you don't need or use.

 

[heysoundude]

Do the tests from not long ago pertaining to connection tuning via MTU still apply to 1Gbps fibre these days? I mean, you're SOOOOO close to seeing the 4 magical digits to the left of the decimal, why not go for it?

 

[Tech9]

I would recommend using the default blue WAN port on RT-AX86U and 940Mbps is the maximum throughput for Gigabit Ethernet. In my own experience the green additional 2.5GbE port on external controller is less stable as WAN. No change is needed, IMO.

 

[tnpapa]

I would recommend using the default blue WAN port on RT-AX86U and 940Mbps is the maximum throughput for Gigabit Ethernet. In my own experience the green additional 2.5GbE port on external controller is less stable as WAN. No change is needed, IMO.

I have been using the 2.5 port as my WAN port for years and it's rock solid for me. Speed tests are 1230mb on the router which is what my ISP supplies and agrees with the speed test built into my ONT.

 

[Tech9]

This specific router model was manufactured with different Broadcom/Realtek 2.5GbE controllers and the user experience may vary.

 

[tnpapa]

This specific router model was manufactured with different Broadcom/Realtek 2.5GbE controllers and the user experience may vary.

I have the same router.

 

[Tech9]

I have the same router model too. What's inside as hardware may be different though with different drivers running it.

 

[tnpapa]

I have the same router model too. What's inside as hardware may be different though with different drivers running it.

 

[Tech9]

This is the CPU, it's the same. What may be different is the 2.5GbE port controller. The router has few hardware revisions.

 

[tnpapa]

Ok, now you have my interest peaked. Is there a way to see which controller I have short of opening the case?

 

[Tech9]

There was actually via SSH and I remember my router has Broadcom version, but lost the way to get this information somewhere in my files. Haven't played with this router for a while... perhaps @RMerlin can help. If yours is working reliably - it's a good thing. The issue is more compatibility to the modem port related and less the type of controller used.

 

[tnpapa]

I found it.

RT-AX86U:/# ethtool -i eth0

driver: Broadcom Ethernet Interface
version: 7.0
firmware-version: N/A
expansion-rom-version:
bus-info:
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-register-dump: no
supports-priv-flags: yes

 

[Tech9]

If everything is working properly - don't touch!

 

[tnpapa]

Funny thing is I am trying to help out someone with a AX56U who just got fiber and for some reason he is getting only half the download speed when he turns on IPv6 as measured by the built in speed test.