IPv6 Pass through doesn't work when nat hardware acceleration turns on [AC68U]

[timeregained]

With asuswrt-merlin.ng version 384.10_2:

If the nat hardware acceleration turns on and IPv6 is set to Passthough, the system log was flood with :"kernel: osl_pktfastfree: free skb for NULL ctfpool". Network devices could get its own ipv4 & ipv6 address but cannot access to internet.

However, IPv6 passthrough works well when the nat hardware acceleration is set to off.

I have tested and verified this would happen on all version of merlin-ng till very lastest 384.10_2.

I have searched this topic and find a samilar case as https://www.snbforums.com/threads/ac66u-ipv6-dmz.38060/ , but it seems ending to using NAT acceleration is set to off - IPv6 passthrough.

Would someone please help to give some advices on this issue?

Thanks a lot!

 

[Mikiya]

Hi,
I know this post is really old, but i have the same issue with my AC68U. I need Passthrough to be able to use IP V6. But if i enable it with accelerations "CTF+FA", i have a strange behavior, instabilities and lots of problems. Without Passthrough, with "CTF+FA", no problems at all.
And if i disable "FA" acceleration only, it seems ok, stable, but i hit 100% on CPU and cannot use full ISP bandwith (1Gb/s)

Does anybody else (except timeregained in 2019) encounter this issue with this model ? And perhaps more important : is AC68U the only model impacted ?

Thanks !

 

[L&LD]

Is this an original RT-AC68U? What firmware are you using?

I'd imagine the issue to have been resolved by now.

Take a backup of your settings and the firmware you're currently using, flash the latest firmware version and do a full reset to factory defaults and then test. If it works correctly then, you need to redo your settings one by one, testing as you go.

 

[Mikiya]

I use the latest Merlin firmware and i already try a full reset (without settings backup to be sure).
I just try again this morning and ... no it's not stable

in log i can see this error spamming "Nov 30 08:17:02 kernel: osl_pktfastfree: free skb for NULL ctfpool", no here whithout Passthrough.

PS : i don't know original or not...

​

CPU Model	BCM470x - Cortex A7 ARMv7 revision 0 (Cores: 2)
CPU Frequency	800 MHz

Edit : this post seems related too with this error and v6 issue : https://www.snbforums.com/threads/c...sthrough-and-nat-hardware-acceleration.56522/

 

[L&LD]

Yes, the 800MHz dual core is the original.

You need a much more powerful router today to fully utilize 1Gbps ISP speeds with the features you want/need.

 

[Mikiya]

With "CTF+FA" i can reach 1Gb. But if i want IPv6 (with Passthrough), FA has problems and without it, indeed, i can't reach 1Gb, CPU is too weak.
Soon i should replace it with a GT-AX6000 but i want to be sure to solve my problem with it ^^
That's why i want to know if anybody know why FA has problem with Passthrough.

 

[L&LD]

The processor is just not strong enough. I can't recall anyone having this issue on newer hardware. But if I'm wrong, I'm sure someone will point it out quickly enough.

 

[Mikiya]

Thanks
Hum i found other links for this issue : https://www.snbforums.com/threads/r...4-are-now-available.61694/page-18#post-555894 and https://app.bountysource.com/issues...not-work-when-nat-hardware-acceleration-is-on , all linked with 68U model. So it seems to be related to this model (or similiar), a router change should be a good solution.

 

[sfx2000]

If the nat hardware acceleration turns on and IPv6 is set to Passthough, the system log was flood with :"kernel: osl_pktfastfree: free skb for NULL ctfpool". Network devices could get its own ipv4 & ipv6 address but cannot access to internet.

If i recall, there were reported issues with CTF (NAT Acceleration) and IPv6 on the older platforms.

 

[Mikiya]

Just as a note for anyone interested : I switch to a GT AX6000 model and with the same conf (ipv6 Passthrough+ CTF/FA accelerations) i don't have any problems so it's an issue for old plateform like my 68U, you are right !