cannot even surf lowyat forum when ipv6 is on.. already turn it off

I can surf but slow respond from the server if on IPv6.

Hi..you have v6 on both WAN and LAN interface ?

I don't have this problem in my setup. I only request dhcp-pd which I get a /64 and my WAN has no v6 address. My WAN MTU is 1492 and LAN is 1500. I'm using OpenWRT if it matters.

No stuttering/buffering issues when accessing Youtube.

Bro, can you provide some guides on how to use IPV6 on OpenWrt?
Some pictures would be extra helpful.

Thanks in advance.

This post has been edited by Moogle Stiltzkin: Jul 15 2017, 11:02 AM

Can post it here?

Hi..I'm still on Backfire btw..

I've no GUI setup..my setup is scripted..so I dont have issues getting dynamic dhcp-pd as my scripts take care of flushing/reassigning the new /64 prefix if I reconnect.

I'm using radvd together with Wide dhcp client/server btw

I also have 2 default routes added for redundancy as I notice the current default route seems to dissappear after awhile when the lifetime of the dhcp lease expires.

This post has been edited by Moogle Stiltzkin: Jul 15 2017, 11:02 AM

I just got back and took another look at my mtu. WAN MTU is 1492 but advmss is set to 1432. This is the MTU on my default route. advmss is the MTU advertise to the remote side when you connect to them, youtube, lowyat, etc..

I see 2 different advmss MTU's on my end:

1440 = LAN /64
1432 = redundant 2000::/3 [RFC4291]
1432 = default route

You could try using these MTU's and see if it makes any difference.

Christopher_LK
So is your MikroTik works on v6 now?

Basically I'm having the same setup like yours ...

This is where I'm having problem ...
WAN can get both v4 & v6 once connect, but the LAN seem need to wait around 5~20mins (similar to those ASUS routers). If lucky, may be the LAN interface can get v6 after 5~15mins of waiting, then no problem to test/visit on those v6 sites. But later, say 1/2 hour or few hours later wake up next day, my PC can't test/visit v6 sites
It's like now you have it then you don't

I could be wrong, I do notice if I put all 3 interfaces (LAN/WAN/WAN6) MTU to same value (say 1480 or 1492), then high chance the LAN can get v6

I don't have such irregular/inconsistent issue on my RB750 & ASUS routers ... really not sure what went wrong ...
Might consider to test on AA12.09 later on

Both your AC68 & my AC56 use FW 3.0.0.374.xxx which has broken IPv6
Whereas the other 3 ASUS routers (N16,N66,AC66) is on FW 3.0.0.374.2xxx which has no problem.

I'll bring this up with ASUS, hopefully will release new fix soon

Normally LAN MTU is 1500 on the router, so PC's MTU should also be 1500. The public facing interfaces, WAN/WAN6 would share the same MTU 1492 since it's PPPoE. The advmss MTU is normally lower, in my case 1432.

If 1/2 hours later and your v6 connection is broken, check your default route on the router. In my case it goes missing. Adding it back manually resumes v6. But of course this is troublesome. The default route gets added back later when the dhcp lease is renewed. So for me I add a second route pointing to the WAN interface. This is normally a static route.

ip -6 ro add 2000::/3 dev pppoe-wan

at first, it is working fine..
but this few days, all ipv6 address are not working properly..

i am using one chrome extension called IPvFoo..
I can see what ip address it is trying to load for that hostname.

When I enabled ipv6, It can't get any ipv6 address, and no fall back to ipv4 address. Which cause some page not to load.. like lowyat forum..
Where else when I disable ipv6, it can load ipv4 address properly..

Are you using IPv6 nameservers along IPv4 nameservers ? Which IPv6 nameservers are you using ?

Try using Google's public IPv6 nameservers or OpenDNS public IPv6 nameservers and see if that helps.

Try this in Chrome: chrome://net-internals/#dns

It will show you what nameservers you are using.

@klseet no its not working, it just give me status error... sad case

hmm... it's time to get a new router because I'm pretty sure my 3rd generation TP-Link WD-8960N doesn't support IPv6.

I'm rather new with IPv6, and by the look of this thread it's not a smooth sailing yet. Nevertheless still a good progress.

i am using google public ipv6 dns server...

Anyone with info on setting up ipv6 for Asus AC68U?

ASUS R&D team is fixing the IPv6 problem, so have to wait for ASUSMY to post the new firmware here...settings are

IPv6 Mode - Native
DHCP-PD (On)

then the rest are defaults

I post it previously. but it seems that on unifi, TM's default setting for MTU as 1472 but I'm been running 1480 for weeks already without any issue.
Another issue(?) I'm seeing is that it takes awhile(few minutes after connected into streamyx) before wan ipv6 is available. I'm not quite sure why is that the case.

nevermind, Problem fixed by itself.. Just enable ipv6 and it work again...
Not so stable ipv6 lol