IPv6 prefix delegation not working with 24.7.1-.3

[franco]

Unless the DHCPv6 rule is not in place or not matching, but LL to LL looks normal to me. And since it's UDP ICMP patches wouldn't really matter.

[franco]

Here is the ultimate revert kernel

https://github.com/opnsense/src/issues/218#issuecomment-2321096627

to test your theory. Otherwise this is a configuration issue perhaps.


Cheers,
Franco

[doktornotor]

Now, I spotted this line...

https://github.com/opnsense/src/commit/164bfe67604#diff-efb487014794d10f6658bf2252b545ad5d64469bd0bc9dbde25dfab3a9b0ab9cR6488

Not so entirely sure about UDP being unrelated to ICMP any more.  :o ???

(My brain is dead, someone else please read the surrounding code.)

[franco]

TGIF.

[doktornotor]

For more amusement, try

Code Select Expand

git blame on that line.  ;D

[Cljackhammer]

IPv6 Prefix delegation is working fine for me. Standard configuration using track interface. Send prefix hit only. Comcast is my ISP for home and business.

Opnsense screenshot: https://imgur.com/a/UswlxyF

[Cljackhammer]

2 delegated prefixes. IPv6 connectivity (LAN and WAN) works as well. OP's issue might be related to his configuration or ISP. My setup isn't fancy at all. It's a standard configuration.

[imk82]

That said, I'd disable it altogether and never look at that checkbox again.

Ok. Will do. As you said, the rules created automatically look good and this should not happen logically.

2 delegated prefixes. IPv6 connectivity (LAN and WAN) works as well. OP's issue might be related to his configuration or ISP. My setup isn't fancy at all. It's a standard configuration.

As mentioned in my first post the config is equal to before the upgrad and working since years with the same ISP. This is definitly no ISP problem and related to the update.

Here is the ultimate revert kernel

https://github.com/opnsense/src/issues/218#issuecomment-2321096627

to test your theory. Otherwise this is a configuration issue perhaps.

Cheers,
Franco

Was this comment targeting my problem? How can I test / help tracking down the problem further (reverting dhcp6c didn't work).

On small difference in my configuration to standard: I am not using the default WAN interface but a custom created one (vlan) and it's parent (physical) interface is not assigned.

May there be hard coded things IPv6 related things nailed to the name "WAN" somewhere?

Best regards
Robert

[meschmesch]

As mentioned in another post (to which I received no answer), I have the same problem. IPv6 prefix delegation working for years. After upgrade to 24.7 the delgation only works for WAN and LAN, not for the further interfaces (all track WAN interface). Differently to imk82, I am using the default physical WAN interface, so it shouldn't be a WAN issue...

As I further mentioned in another post, I ticked "Allow manual adjustment of DHCPv6 and Router Advertisements" which before 24.7. allowed me to select a virtual Source Address for Router Advertisements. This option disappeared after the update and now only "automatic" is selectable.

UPDATE: It works, don't know why. After a while it worked again with 24.7.3_1. Further, as a change I had to modify my previously used CARP Address to fe80::192.168.2.1/64 reverting from fd00:: ... used previously. Now I can select the CARP interface for HA.

[doktornotor]

I must be missing all the wonderful use cases,  using such boring tactics like having one track interface and setting up all the rest to be static.

[imk82]

I must be missing all the wonderful use cases,  using such boring tactics like having one track interface and setting up all the rest to be static.

Just to keep topic of this thread focussed and for clarification:

• my problem starts already with the delegation of the prefix from my ISP to my "wan" (it is a custom one, not the on existing by default) interface
• I have one interface configured as tracking one, but since the prefix of the ISP is not delegated correctly, this is also no longer working
• my config and ISP has not changed since before 24.7.1
• since 24.7.1 my "wan" interface is not consuming a prefix from my ISP anymore
• reverting dhcp6c to pre 24.7 version is not fixing the problem
• if I get requirements how to I will help to track this down

Best regards
Robert

[imk82]

Hi all,

has someone maybe a good source or (simple) documentation for for the packets involved in which order when a prefix delegation is done between DHCP client and server?

To bring things forward, I want to try to capture packets on my "WAN" interface and have a look where things stop. But I need a reference what is the "correct" flow

Thanks and best regards
Robert

[franco]

What's odd here is the claim that 24.7.1 is the bad version, when in reality only 24.7.2 changed dhcp6c and there is something weird going on there (see other thread). Sure, 24.7.1 introduced other problems, but the triage here just doesn't feel consistent.

As far as packet captures go that's pretty useless since we need to know what dhcp6c does. Enable debug under System: Interfaces: Settings and reboot. The dhcp6c logs tell us about all the communication that is being done (and why) and in most cases where a prefix is missing the server will likely not have sent it in the first place.


Cheers,
Franco

[imk82]

What's odd here is the claim that 24.7.1 is the bad version, when in reality only 24.7.2 changed dhcp6c and there is something weird going on there (see other thread). Sure, 24.7.1 introduced other problems, but the triage here just doesn't feel consistent.

As far as packet captures go that's pretty useless since we need to know what dhcp6c does. Enable debug under System: Interfaces: Settings and reboot. The dhcp6c logs tell us about all the communication that is being done (and why) and in most cases where a prefix is missing the server will likely not have sent it in the first place.


Cheers,
Franco

Hi Franco,

please find the requested log attached. As far as I can see there is a /56 prefix (I removed some parts of it, wasn't sure about privacy) occurring in the log, but later it says contains no prefix. Weird.

Do you have an idea how to go on?

Thanks and best regards
Robert

[franco]

Hi Robert,

As I see it it's asking multiple times, also interrupted due to SIGHUP reconnect, getting multiple answers but eventually refusing to give out another prefix and that's where it stops as expected.

Seeing that PPPoE is involved I'd like to ask you to try the following:

https://forum.opnsense.org/index.php?topic=42081.msg211107#msg211107

I'm working on this at the moment anyway...


Cheers,
Franco