Last try - 24.7.7 keeps crashing due to IPv6

[Server07]

Hello,

after frustrating weeks on trying to make Opnsense run again after upgrading to latest version, here my last try to get it resolved, otherwise I need to switch to alternative solutions... hope you can help and I try to better describe now. Opnsense has really great functionality but must be stable...

It was running fine for last year and problems startet out of sudden over last month with upgrades...

I'm getting IPv4 & IPv6 from ISP without issue, no error and all running fine. After sometimes 6/12/24h out of sudden below error appear in log, and 15-30min later, Opnsense has not more LAN -  reload services via shell does not help but only restart helps!

Configuration:

- Opnsense 27.7.7 (fresh install meanwhile + load minimum config - but also did not help)
- ISP - Deutsche Glasfaser (WAN DHCPv6, Prefix delegation size 56) all other default
- LAN (Track Interface WAN + manuell RA: Managed )
- no Vlans

DHCPv6 seems to work fine for ISP, and trying to use e.g. SLAAC was not successful.

LAN
192.168.0.1/24 - 2a00:6020:4347:xx01:2xx:2exx:fe96:7406/64
WAN
100.118.xx.250/16 - 2a00:6020:1000:xx::47x9/128

General Log:
2024-11-03T09:02:38   Error   opnsense   /usr/local/etc/rc.newwanipv6: The command '/usr/sbin/daemon -f -p '/var/run/dhcpleases6.pid' '/usr/local/opnsense/scripts/dhcp/prefixes.sh'' returned exit code '3', the output was 'daemon: process already running, pid: 63828'
2024-11-03T08:50:54   Warning   radvd   exiting, 1 sigterm(s) received   
2024-11-03T08:50:54   Error   opnsense   /usr/local/etc/rc.newwanipv6: The command '/bin/kill -'TERM' '59777''(pid:/var/dhcpd/var/run/dhcpdv6.pid) returned exit code '1', the output was 'kill: 59777: No such process'   
2024-11-03T08:50:50   Warning   radvd   exiting, 1 sigterm(s) received   
2024-11-03T08:50:50   Warning   opnsense   /usr/local/etc/rc.linkup: dhcpd_radvd_configure(manual) found no suitable IPv6 address on lan(re0)   
2024-11-03T08:50:49   Warning   opnsense   /usr/local/etc/rc.linkup: dhcpd_dhcp6_configure() found no suitable IPv6 address on lan(re0)

After few minutes, the LAN hangs (but no further log) - only restart from shell can recover...

[meyergru]

Why don't you try with RA: "unmanaged" or "assisted" at most and radvd only? Many client devices do not support DHCPv6 anyways. I also use "request prefix only" and the new "Optional prefix ID" feature to give the WAN interface an IPv6 address out of the GUA prefix range.

I have three instances running like that with DG and no problems.

[Server07]

Hello,
DG requires "DHCPv6-Mode stateful" if I read it correctly in the requirements doc.

Options SLAAC:
"Unmanaged" for SLAAC (A flag) - ISP did not give me IPv6 in SLAAC (request prefix only on/off both tried)

Options DHCP:
"Managed" for Stateful DHCPv6 (M+O flags) - currently used but failing
"Assisted" for Stateful DHCPv6 and SLAAC (M+O+A flags) - try again now
"Stateless" for Stateless DHCPv6 and SLAAC (O+A flags). - should not work as not "stateful" or?

By keeping focus on Interfaces: [WAN] - DHCPv6 + RA mode (Managed or Assisted) :

In the field Services: ISC DHCPv6: [LAN]:
- I still need to activate "Enable DHCPv6 server on LAN interface" or would that double vs setting in RA(Managed or Assisted) ?
- Do I have to write for Prefix Delegation Range also 56 (default was 64, just recognized)?
- Is the setting "request prefix only" only for SLAAC or also for DHCP reasonable?

[meyergru]

You are mixing up DHCPv6 as a client (i.e. OpnSense vs. DG) and DHCPv6 as a server (OpnSense vs. your LAN clients). You do not need the latter.

You set "DHCPv6" as IPv6 configuration type on the WAN interface, then "Track WAN Interface" on your LAN interface.

Then, you set RA: Assisted or Unmanaged in Services : Router Advertisements and disable the DHCPv6 server (under "Services") for your LAN accordingly.

There are no RA settings for your WAN interface, because you use DHCPv6 for that. Set "Use Prefix only" and "Optional Prefix ID" with an ID that is different from your LAN Prefix ID.


BTW: Just follow my instructions here.

[Server07]

Many thanks already - I think that already clarified two wrong items. Präfix ID was not different and disabled now DHCPv6 für LAN. Can imagine that cause double process and now all LAN/WAN/Wireguard has same prefix ...  Will report if issue remains...

[Server07]

well, double DHCP6 I assume was killing the server. Now it runs as should !Many thanks!