IPv6 prefix delegation not working with 24.7.1-.3

[REB00T]

Do you have "Request only a prefix" unset? It would be better to set this option if that's the case. If it's already set we need to try and ignore this zero lifetime NA that doesn't even provide an address.

I don't know how similar this issue is to mine but setting this does actually give me a prefix. I will play around with this some more, but it seems promising so far. I will also try the new dhcp6c patch. I am available to test theories if you want.

[REB00T]

Robert,

As per my earlier comments I wrote this patch to try https://github.com/opnsense/dhcp6c/commit/d2e5fb474f

# pkg add -f https://pkg.opnsense.org/FreeBSD:14:amd64/snapshots/misc/dhcp6c-20240907_3.pkg

Reboot to see if it helps.


Thanks,
Franco

It seems to have completely fixed my case. A prefix, (with an address for the interface itself) is picked up immediately, similar to pre 24.7.4. If you want anything else tested, I will probably be available.

[franco]

Still no specialist in that topic, but I think the pattern of the log changed somewhat since 24.7.3.

To be frank more than enough people report such very particular issue we've never had before specifically at this time in the way the protocol works during the request itself that I doubt this is something a firewall would interfere with on such a fine-grained specific level... which leads me to believe some specific server software for DHCPv6 got updated and now exhibits this behaviour (no clue if intentionally or due to a bug).

I mean we can fix the bug in the client, but we also have to consider the client was able to handle this for a very long time already.

It seems to have completely fixed my case. A prefix, (with an address for the interface itself) is picked up immediately, similar to pre 24.7.4. If you want anything else tested, I will probably be available.

That sounds interesting. While at this and your topic in particular I also think that it may be practical to move the PPP log to the system log because we do seem to miss correlation between the two an it's hard to infer what PPP(oE) did while we look for clues in the main log file doing things that we don't know why and when triggered.

The dhcp6c patch will not be in 24.7.5. I've made that mistake before adding too many things in one release before. But we can definitely make 25.7.6 with good feedback on Robert's side. Otherwise we may have to tweak it more.


Cheers,
Franco

[imk82]

Robert,

As per my earlier comments I wrote this patch to try https://github.com/opnsense/dhcp6c/commit/d2e5fb474f

# pkg add -f https://pkg.opnsense.org/FreeBSD:14:amd64/snapshots/misc/dhcp6c-20240907_3.pkg

Reboot to see if it helps.

Thanks,
Franco

Hi Franco,

is this still true for 24.7.5 or will things break if I apply the patch/install the package? Or in the other direction, needa the patch/package a adaption for 24.7.5 before trying it?

And should I install one by one and check the effect or both together?

Can do this now, my box has not that much critical traffic this weekend.

Best regards
Robert

[franco]

Hi Robert,

Sorry for the response delay.  It's still true but the package moved to a new rebuild (but holds the same source code as discussed):

# pkg add -f https://pkg.opnsense.org/FreeBSD:14:amd64/snapshots/misc/dhcp6c-20240919_1.pkg

Just update to 24.7.5 and see how that goes as a separate data point. Then install the updated client and reboot again to see if that changes things.


Cheers,
Franco

[imk82]

Hi Robert,

Sorry for the response delay.  It's still true but the package moved to a new rebuild (but holds the same source code as discussed):

# pkg add -f https://pkg.opnsense.org/FreeBSD:14:amd64/snapshots/misc/dhcp6c-20240919_1.pkg

Just update to 24.7.5 and see how that goes as a separate data point. Then install the updated client and reboot again to see if that changes things.

Cheers,
Franco

Hi Franco,

good and bad news.

Did another series of tests to track this down further. Just as a recap, my setup is:
* OPNSense setting vlan7 (necessary for my provider Deutsche Telekom) and doing PPPoE dialing
* Modem directly connected to the OPNSense Box not setting a vlan7

1. installed 24.7.5 -> not working (see attached log)
2. installed patched dhcp6c client on top of 24.7.5 -> not working (see attached log)
3. connected a OpenWRT box in the exact way to the modem as the OPNSense box and let it set vlan 7 -> working
4. reconfigured OPNSense to NOT set the vlan (using the underlying interface directly) and let the modem set the vlan -> working (can provide log if needed, forgot to collect)

Based on this there are three new data points:
* it is no longer sure, that the problem was introduced with 24.x.x (I doubt so). But I reconfigured the vlan thing at the same time (mentioned it in earlier posts already)
* it is no provider side issue
* there is a problem with OPNSense and IPv6 PD when it is based on a vlan instead directly at the physical interface

What do you think how we should go on here, is there anything I can test for you?

I think a bug in the dhcp6 client is not longer likely, more one deeper in the network stack?

Best regards
Robert

[blusens]

Could my problem be related to this topic? One of my opnsense boxes has erratic behavior since 24.7.x . Managed radvd stopped working but when I switch to Assisted, only hosts that don't have a static reservation are getting an IP (slaac i think).

Another opnsense box in a different location but on the same ISP and with almost the same settings doesn't have this issue.

[Bash5244]

i am on 24.7.6 and the ipv6 doesn't seem to work correctly after a while (after the WAN connect is reset)

everytime i see the following logs , the ipv6 connection on the network stop working.

2024-10-10T10:00:13   Notice   dhcp6c   XID mismatch   
2024-10-10T10:00:13   Notice   dhcp6c   get DHCP option domain search list, len 15   
2024-10-10T10:00:13   Notice   dhcp6c   get DHCP option DNS, len 32   
2024-10-10T10:00:13   Notice   dhcp6c   IA_PD prefix: 2406:3400:410:9d80::/60 pltime=604800 vltime=604800   
2024-10-10T10:00:13   Notice   dhcp6c   get DHCP option IA_PD prefix, len 25   
2024-10-10T10:00:13   Notice   dhcp6c   IA_PD: ID=0, T1=302400, T2=483840   
2024-10-10T10:00:13   Notice   dhcp6c   get DHCP option IA_PD, len 41   
2024-10-10T10:00:13   Notice   dhcp6c   DUID: 00:01:00:01:2b:80:15:fe:28:b1:33:00:8c:89   
2024-10-10T10:00:13   Notice   dhcp6c   get DHCP option client ID, len 14   
2024-10-10T10:00:13   Notice   dhcp6c   DUID: 00:03:00:01:88:1d:fc:68:3a:00   
2024-10-10T10:00:13   Notice   dhcp6c   get DHCP option server ID, len 10   
2024-10-10T10:00:13   Notice   dhcp6c   receive advertise from fe80::8a1d:fcff:fe68:3a00%pppoe0 on pppoe0   
2024-10-10T10:00:13   Notice   dhcp6c   reset a timer on pppoe0, state=SOLICIT, timeo=13, retrans=3712916   
2024-10-10T10:00:13   Notice   dhcp6c   send solicit to ff02::1:2%pppoe0   
2024-10-10T10:00:13   Notice   dhcp6c   set IA_PD   
2024-10-10T10:00:13   Notice   dhcp6c   set option request (len 4)   
2024-10-10T10:00:13   Notice   dhcp6c   set elapsed time (len 2)   
2024-10-10T10:00:13   Notice   dhcp6c   set client ID (len 14)   
2024-10-10T10:00:13   Notice   dhcp6c   Sending Solicit


I have the 'get prefix only' option checked and i am using NPTv6 as well

[Bash5244]

I reverted dhcp6c back to v20240919 and everything is working flawlessly again...  :|

[Context0881]

Hi,
I also encounter weird behavior with IPv6 since september
Unfortunately my technical knowledge's very limited and english not my primary language but i will try to report the problem.

I connect to my ISP with fiber link and PPPoE. He give me /48 and everything's good since 1,5+ years.

My settings in WAN interface:
type DHCPv6
Configuration mode basic
Use IPv4 connectivity check
Request prefix only check
Send prefix hint check
no optional ID or interface ID
(it has always worked with those settings)

The problem is the same with the 2 OPNsense boxes that I have (both connected to the same ISP, same settings, but different location)
WAN is getting IPv6 with gateway monitoring OK. But it seems PD broken because LAN (track interface mode) doesn't get IPv6 and so are the devices behind.
Tried various settings / multiple reboots / PPPoE reload nothing really seems to correct the problem and sometimes with no warning PD work LAN get it's delegation and everything work as intented and can stay for days like that (but since i'm always tinkering with my homelab i often reboot the OPNsense box and thus loose IPv6).
I do not like IPv4 and really prefer to use IPv6 everywhere I can.

Updated today to 24.7.6 same problem happen unfortunately

Please excuse my english
Regards

[Static7158]

The same for me.
After a restart, DHCPv6 is stopped, no prefix delegation. At some point, out of nowhere, DHCPv6 and prefix delegation are running and all devices have IPv6 addresses. But this only lasts for a limited time, after a few hours the IPv6 disappears again. Restarting only leads to DHCPv6 being stopped again. Unfortunately, 24.7.6 has not changed this.

[Bytechanger]

Same to me.

I ve updatet opnsense from 24.7.4_1 to 24.7.6.
Now Im getting the problem no ipv6 Prefix.
It took me hours, now I see this post.

I will try to get to 24.7.4 back or is there a bugfix??


Greets

Byte

[wgelyjr]

Checking in, updated to 24.7.6 on Friday 10/18 and my prefix doesn't 'stick' longer than an hour or so after renewing my lease. Re-renewing my lease on WAN fixes it briefly, but it will inevitably go back down. ISP says my lease is not getting claimed. XID Mismatch is present in the logs and seems to correlate with IPv6 going down.

Reverting kernel and opnsense to 24.7.4. Will update if that does not fix my issue. Looking forward to a fix.

[Bytechanger]

Hi,

is the prefix delegatoin issue fixed on 24.7.7?
Has someone test it?

Greets

[Bytechanger]

Hi,

the error still exists!
I get no ipv6 over delegation from my fritzbox!
Whe I downgrade, it works fine!

@franco: Is there a chance that the error will be repaired soon?
My last working OPNSense ist V 24.7.5_3


Greets