Local ISP weird behaviour w/ IPv6 via DHCP6

YoLo88 · Jul 17, 2024, 9:54 PM

@Gertjan said in Local ISP weird behaviour w/ IPv6 via DHCP6:

You didn't show the log lines where it eventually got eventually a valid DHCP6 lease ?

Thank you very much for your response!!

Those were the first set of logs @17:26. It only get's a valid IPv6 lease if I disconnect/reconnect the WAN interface via the WebUI. And it reliably does get an IPv6 address every time I do this. and then.... 10 minutes later it drops and never recovers.

This must be a setting somewhere to replicate how the Fritz box was getting IPv6 because that would ... just ... work.

YoLo88 · Jul 17, 2024, 10:01 PM

@YoLo88 said in Local ISP weird behaviour w/ IPv6 via DHCP6:

send renew to ff02::1:2%pppoe0

Is the problem this PPPoE IPv6 address - "ff02::1:2%pppoe0"

Jul 18 09:57:49	dhcp6c	86580	Sending Solicit
Jul 18 09:57:49	dhcp6c	86580	set client ID (len 14)
Jul 18 09:57:49	dhcp6c	86580	set identity association
Jul 18 09:57:49	dhcp6c	86580	set elapsed time (len 2)
Jul 18 09:57:49	dhcp6c	86580	set option request (len 4)
Jul 18 09:57:49	dhcp6c	86580	set IA_PD prefix
Jul 18 09:57:49	dhcp6c	86580	set IA_PD
Jul 18 09:57:49	dhcp6c	86580	send solicit to ff02::1:2%pppoe0
Jul 18 09:57:49	dhcp6c	86580	reset a timer on pppoe0, state=SOLICIT, timeo=1135, retrans=108036

Where the hell does that come from? I can't ping it and it doesn't look like it relates to either the fe80 link local addressing or real IPv6 addressing that I'm getting from my ISP...

YoLo88 · Jul 18, 2024, 6:14 AM

Ahh, FF02::1 is Link-local multicast address All nodes (broadcast)

Gertjan · Jul 18, 2024, 6:14 AM

@YoLo88

As this is IPV6 and IPv4 over PPPoE, did you set a MTU value less then 1500 ?

This one :

@YoLo88 said in Local ISP weird behaviour w/ IPv6 via DHCP6:

Jul 16 17:36:41 rc.gateway_alarm 99403 >>> Gateway alarm: WAN_DHCP6 (Addr:[fe80::xxx:xxxx:xxxx:xxxx]%pppoe0 Alarm:1 RTT:1.447ms RTTsd:.421ms Loss:21%)

is strange.
When the 10 minute DHCP6 lease is over, the IP6 info is still valid. Lease renewal starts to happen half way the lease duration. That is, DHCP4 works like that. When a device receives a DHCP4 lease valid for 6 hours, renewal start at 3 hours.
If that is the same for IPv6, then why ..... there is a gateway alarm = ping6 doesn't pass anymore.
I'm pretty sure that has nothing to do with the DHCP6 lease renewal.
Was the pppoe interface already reset before that gateway alarm line .
The pppoe connection itself went bad ? The pppoe renewal is a slow process. And while that's in progress, the IPv6 that goes over it can't be created.

Does the IPv4 use the same pppoe connection ? IPv4 doesn't complain / stays in a working condition ?

I'm just brainstorming here. It's years now my ISP left pppoe for what is was : perfect for the waste bin.

YoLo88 · Jul 21, 2024, 9:36 PM

@Gertjan Thanks again for your input. Much appreciated.

The MTU appears to set itself to 1492

I tried disabling gateway monitoring but it didn't make any difference.

IPv4 and IPv6 are sharing the same PPPoE connection yes, I have the "Use IPv4 connectivity as parent interface" - "Request a IPv6 prefix/information through the IPv4 connectivity link" option ticked and yes IPv4 is fine. It renews without a problem.

My ISP is garbage for tech support. I can't get anyone even remotely technical to speak to me. They just tell me to put the Fritz box back on there or it's my problem to figure out which is kind of fair enough. This IPv6 connection is stable on Fritzbox but not on PFSense. Therefore, it must be a setting in PFSense that I can tweak to fix the stability.

YoLo88 · Jul 21, 2024, 9:36 PM

What about https://redmine.pfsense.org/issues/13237 ? Some notes in there about strange behaviour that happens repeatedly unless the firewall is physically rebooted? Going to give it a cold boot now and see how that goes...

YoLo88 · Jul 21, 2024, 10:02 PM

Aaaaaaand 13 minutes of uptime and IPv6 is still stable!

YoLo88 · Jul 22, 2024, 5:35 AM

And it lasted about 50 minutes before it died and didn't recover again. So, better but still not great.

Gertjan · Jul 22, 2024, 5:35 AM

@YoLo88

So it did renew 4 times at least, and failed to do so the 5th time ?

YoLo88 · Jul 24, 2024, 10:15 AM

Looks like I was lacking "rapid commit" under advanced IP options. I tried to post instructions here but it keeps getting flagged as Spam. Check out https://www.reddit.com/r/PFSENSE/comments/1duuc6o/ipv6_troubles_unstable_pppoe_ipv6_address_via/ for the full post.