OpenVPN on the BCM4912 (ZenWiFi Pro XT2 or GT-AX6000)

[xwildx]

@RMerlin do you know if the new router asus gt ax6000 support pppoe with a 1500 mtu (mtu 1508 on the wan port - RFC4638)?

 

[RMerlin]

@RMerlin do you know if the new router asus gt ax6000 support pppoe with a 1500 mtu (mtu 1508 on the wan port - RFC4638)?

The WAN/PPPoE code is identical to all other models.

 

[xwildx]

The WAN/PPPoE code is identical to all other models.

I confirm that it work on an rt-ac86u or a ac3100.

On the asus ax88u it doesnt work, not sure why the driver won’t allow it

if you try to manually to set the wan port to mtu 1508 it give this :


admin@RT-AX88U-06A0:/tmp/home/root# ifconfig eth0 mtu 1508 up
ifconfig: SIOCSIFMTU: Invalid argument

 

[RMerlin]

I confirm that it work on an rt-ac86u or a ac3100.

On the asus ax88u it doesnt work, not sure why the driver won’t allow it

if you try to manually to set the wan port to mtu 1508 it give this :


admin@RT-AX88U-06A0:/tmp/home/root# ifconfig eth0 mtu 1508 up
ifconfig: SIOCSIFMTU: Invalid argument

I thought you were referring to whether the firmware itself supported it.

This is a different switch with a different SDK, you probably need to directly configure the switch itself. You might possibly need to enable larger MTU support first.

 

[xwildx]

@RMerlin do you know if there is a manual way by the command line to do it?

On the interface here are my settings

I also have jumbo frame enabled

Many thanks,

 

[RMerlin]

@RMerlin do you know if there is a manual way by the command line to do it?

I don't know, I never really looked at it.

 

[xwildx]

I just got the gt ax6000.

It still doesnt support the baby jumbo frame, same issue like the AX88U.

I also tested a Bell hhub 3000 and 4000 and it working, it is supporting baby jumbo frame without issue.

The bell modem 4000 give around 20 mbps more than the gt ax6000 on a gigabit connection but I think it is due to the baby jumbo frame that is working well.

 

[xwildx]

Here is my comment after 1 day of use of the GT AX6000 (version Asusmerlin 386.6)


The booting and GUI is faster than the AX88U, we can definitely see an improvement.

Temperature is about the same

GT AX6000 temperature : (I have more than 65 devices on the wifi and on the network).

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Temperatures	2.4 GHz: 49°C - 5 GHz: 52°C - CPU: 76°C

I found small issues on the GT AX6000.

Issue #1 ) There is a new setting and I have kids that always push all the buttons in my house.

Is it possible to have a toggle option in the WPS Button behaviour to just do nothing? Like (off) ?



Issue #2) I also tried to do a backup of the jffs

It seems that the file is not found, not sure why? I did a backup using SSH.


Issue 3) Not really an issue just a remark

QoS on Cake is also giving 370-380 mbps on a fiber gigabit connection. (Maybe around 10 mbps more than the AX88U, it's hard to see the improvement from the 200 mhz increase).

Issue #4) The issue (already described in the previous post)

PPPoE is limited to 1492 (the router doesnt support MTU 1500)

Basically, the WAN port must be using 1508 MTU to be RFC4638 compliant (A MTU of 1500 on fiber + PPPoE 8 bytes = 1508)

All people using a Fiber optical connection with PPPoE (Like Bell, Rogers, etc.) will have this issue. (The issue is not there on old Asus device AC3100, etc.)

It would be nice if someone has a direct contact at Asus to tell them that the router is not meeting the RFC4638 requirement.



Best,

 

[Darkling]

2 weeks ago i had send a support ticket to Asus if they could ad RFC4638 support. The answer i was getting was that there were no plans to add this. I own a AX88U and recieved a answer from the dutch support.

 

[sfx2000]

It would be nice if someone has a direct contact at Asus to tell them that the router is not meeting the RFC4638 requirement.

RFC4638 is not a "requirement" for PPPoE - it's a recommendation only that provides a degree of guidance on how to implement MTU sizes that exceed 1492 - but note that it's optional, and the operator's infra is likely as not to support it.

RFC2516 however, is a hard requirement for MTU not to exceed 1492 with PPPoE

 

[rodrigo2022]

I had the same issue with the RT-AX88U 1 year ago, I got a refund and switched back to old AC86U.

@sfx2000 most of the ISP on fiber optic is RFC4638 in 2022.

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