Ipv6 Address on wan6 but no ipv6-pd after reboot

Installing and Using OpenWrt
1

Hello,
my problem is that i got no public ipv6-pd after an reboot. The wan6 interface got an public ipv6 (2a00: ...) but no ipv6 prefix for this network to delegate. My OpenWRT Powered R7800 hangs behind an FritzBox which is delegating the prefix to the wan6 interface of the openwrt router. I think in general my configuration is ok since i get the prefix on wan6 after restarting the interface! Maybe something is not yet initialized on boot if wan6 wants to request the prefix? But unfortunately I have also observed that the ipv6 connection is lost after a long time (24h+). Does anybody have an idea?

I noticed this problem while i had 21.02.1 installed, then i checked out the current git master from today but the problem still exists.

syslog after fresh boot
Syslog entries after restart wan6 to fix the issue (nothing interesting it think))

*** WAN6 config ***

config interface 'wan6'
        option device 'eth0.2'
        option proto 'dhcpv6'
        option peerdns '0'
        list dns '::1'
        option force_link '1'
        option reqprefix '60'
        option reqaddress 'none'

wan6 gut
wan6 gut968×181 14.4 KB

wan6 nach reboot
wan6 nach reboot963×185 15.4 KB

2

First remove the dns ::1, if you are not using any dns reachable from the wan.
Change the reqprefix to auto and the reqaddress to try.
I'd also suggest to disable the global ula prefix, as it seems that the fritz is already providing one.

3

Thanks for your reply,
The dns entry is correct i´m using unbound as resolver, this cannot be the issue as you read. If i restart the interface with the same config it is working! The config cannot be such invalid, i tried your suggestion alreay (reqprefix all possibilities)

The strange thing is that the prefix (fdea:...) is not the lua from openwrt (fdea:ed36:99b1:8::/61) or fritzbox (fd5e:19da:b486:192/64). And i surely have no other routers in my homelab.

Best regards

4

I have this issue too with a Speedport for Internet access. I'm also restarting the wan6 interface to "fix". So it seems to be a bug of Openwrt.
Btw, whats the command to restart wan6 by terminal/script?

5

ifup wan6

No, but it helps to verify that the defaults are working or not.

The 2 fdea prefixes that you have in the screenshot after reboot are coming from the same source, as the network part of the prefix is the same.
Quickfix would be to run /sbin/ifup wan6 in the /etc/rc.local
As there is not much relevant in the logs, a packet capturing needs to be setup. It is challenging because the problem occurs on boot. If you are interested to try it, let us know.

1 Like
6

It seems the PD is announced in an interval, and wan6 does not get it intsantly on reboot. But by restarting wan6 the prefix seems to be requested instead waiting. But i never waited long enough to be sure!

7

The PD must be included in the DHCP6 Advertise.
If it is not there, it is a question whether the client requested for the prefix or not.

8

Hello @trendy this is the same problem i was facing. You said that my provider giving /64 was a problem. After reboot I'd lose ipv6pd until I manually restart the wan6 interface.

9

Hello,
again i´m really sorry i figured out that a forgotten access point was delegating its lua prefix to my wan network :zipper_mouth_face:

The prefix delegation work´s now as expected! But if i reboot the main router (Fritz!Box) i loose my ipv6 connection. Does the wan6 interface not asking for an new prefix if the connection was interrupted?

@fda After fresh boot do you have any ipv6-pd? Btw: Speedport... my condolences :wink: :wink:

10

Yes, on the ("rooted") Speedport crap there is "dibbler" running.

Another big problem with Speedport: During reboot, it provides 2003:6: ipv6s, but when it is fully connected it changes to 2003:db:. But Openwrt keeps the then invalid 2003:6: additional to to 2003:db: ipv6