[CALL FOR TESTING] PPPoE restructuring and IPv6 improvements

[franco]

Hi,

Due to a user prompt we're going to restructure PPP for the next major release 25.1 in order to be able to allow IPv6-only deployments including using DHCPv6 which isn't possible at all at the moment.

A POC already exists and appears to work, but I'd like to take this a bit further due to related issues such as the infamous "Use IPv4 connectivity" setting. The idea here is to remove it and make it the default, because

(a) everyone including developers have trouble wrapping their head around the concept,
(b) when in reality the opt-in setting is really the default behaviour of PPP-based setups to begin with,
(c) and to achieve running DHCPv6 on the hardware interface beneath PPP simply assign the hardware interface and set it to DHCPv6.

The goal is to finish this change on the development version coming with 24.7.2 for general consumption, but it would be very beneficial to merge backwards-compatible changes to 24.7.x without removing "Use IPv4 connectivity" usage as this progresses and matures. The final code change for 25.1 will then be much smaller and easier to review.

And this is where the call for testing takes off at the moment for everyone running 24.7.1:

https://github.com/opnsense/core/commit/3a9f98843b

# opnsense-patch 3a9f98843b

If you have an PPP(oE) deployment with or without IPv6 try this patch and see if it works like before. I'd like to know of behavioural changes or drop in IPv6 connectivity if previously working so we can refine this together, add it to a 24.7.x release and work on the next batch.


Thanks,
Franco

[meyergru]

With M-Net, this works (did a reboot after the patch).

IPv4: PPPoE
IPv6: DHCPv6

Prefix-only requested and using the new "Optional Prefix ID" feature.

[franco]

Nice, thanks. I finished the pieces for opnsense-devel now. Will test this as good as I can and then we'll revisit after 24.7.2 is out.

Just to be sure: you are using "Use IPv4 connectivity", right?


Cheers,
Franco

[Christophe999s]

Applied the patch, seems to be working in my case.
Attached a screenshot of my settings.
Let me know if you need further details or testing done.

[franco]

@Christophe999s thanks a lot, no further questions at the moment <3


Cheers,
Franco

[meyergru]

Just to be sure: you are using "Use IPv4 connectivity", right?

Yes.

[PhoenixRider]

Just so I didn't misunderstand. Will it still be possible to use the IPv4 connection to get an IPv6 prefix in the future?

Deutsche Telekom continues to work in such a way that primarily an IPv4 connection is established and the IPv6 prefix is ​​requested via the IPv4 connection.

[franco]

Short answer: yes.

Long answer: Yes, though:

1. "Use IPv4 connectivity" option will be removed while making it the default behaviour.
2. PPP will be used even when IPv4 mode is "None" and IPv6 mode is "DHCPv6" by virtue of being assigned to the interface (device name match). This will be new territory.

It would also be possible, later on, to run DHCP on top of PPPoE, but I don't think this will be needed. The key here is the decoupling of when PPP is started regardless of what IPv4 and IPv6 modes are chosen as long as a relevant mode for PPP is being offered (this is fully backwards compatible).

The only downside in the future is for users of disabled "Use IPv4 connectivity" is that in order to keep IPv6 connectivity they need to assign the parent device of the PPP and configure it as a separate interface.


Cheers,
Franco

[PhoenixRider]

Alright. Thank you, franco. This sounds very good!

[beisser]

applied the patch with deutsche telekom (non business) with the checkbox request only prefix turned off and it seems to work normally.
the device came up normally after reboot and connection is established and working as usual.

[phoenix]

I've just applied the patch and rebooted without problems.

The only thing that's happened is my download speed (using speedtest)  has almost disappeared - this is the result after applying the patch: https://www.speedtest.net/result/16604096563 - although this is typical of the five results today and using various download servers for the test.

I've recently upgraded my service to 900Mbbs, I was on the 500Mbps and always had a download speed was roughly 460 Mbps - this doesn't want to go any faster.  I'll have to contact Zen again to see what's happening.

[meyergru]

@phoenix: If you are still on that Intel 4560U, this is probably all you can get... ;-)

[ams_sharif]

After updating the firmware to 24.7.1. Connectivity is intermettintly being interrupted. For instance, any SSH session diconnnects every 30 seconds. This happens when DHCPv6 is enabled.
I also had to re-enter my pppoe username and password and re-link the pppoe interface with the vlan, as the pppoe configurations were gone. The interface itself remained, though
Applying the patch didn't change anything. The use ip4 connectivity is still there. I had to disable DHCPv6 on my WAN to solve the interruptions.
My network adapters are intel i226, 3 of them bridged and used for my LAN.
I'm not sure if this is useful for you to troubleshoot, so let me know if any logs would be helpful

[computeralex92]

I also activated the patch and everything is working without an issue.

IPv4: PPPoE
IPv6: DHCPv6 (with "Use IPv4 connectivity" active)

But I saw there something strange:
It seems that after applying the patch, an additional Gateway appeared.
Background:
To access my DSL modem I configured the interface of the PPPoE connection additionally with a static IP (see attachments).

I'm not 100% sure this appeared with the patch, but I can not remember seeing this interface before applying the patch, therefore I assume the patch is the source of it.

[franco]

I would expect the patch to misconfigure PPP configuration which would lead to permanent connectivity loss or partial loss because it fails to bring up IPv6 connectivity after connecting the PPP. Everything else looks manual or coincidental. It's easy to revert the patch (run the patch command again) and double-check. Especially things like assigned interfaces are what they are. The patch (or 99.9% of the code in general) does not meddle with the local settings at all.


Cheers,
Franco