IPv6 prefix is getting lost

[kbsd]

Hi,

I searched in the forum and the mailing list archives as well as in the Internet in general, but did not find a similar report.

I have a DSL contract with NetCologne (Germany). They have a dual stack configuration. IPv4 and IPv6 were working well with an OpenWRT router connected. I replaced this router with an APU2c4 board with OPNsense 16.7.5. IPv4 is working well. IPv6 does not always work. After a fresh connect, I get an IPv6 address on WAN (pppoe0) and a IPv6 prefix assigned. So the LAN interface (bridge0) does get an IPv6 address as well. After some time, the IPv6 address of the LAN interface gets lost. WAN still has an IPv6 address, but not LAN and the clients in the LAN neither. So in general the configuration seems to be correct to me.

I have extracted some relevant (anonymized) information from the log files and added some comments. You can find it in the attachment.

The WAN interface is configured for PPPoE for IPv4 and DHCPv6 for IPv6. The DHCPv6 config is set to use IPv4 and to send a prefix hint for a /48 prefix, which is what NetCologne offers. The LAN interface is configured to track interface for IPv6.

Can anybody help me? It seems that I get a prefix from NetCologne, but this is not (always) used.

Thanks in advance!

Kind regards
Kay

[kbsd]

Hi again,

I played around a bit and found out, that the LAN interface receives an IPv6 address in case I change anything in the interface configuration. So in case the LAN interface does not have an IPv6 address (prefix from provider is not used), I can go to the interface settings, change e.g. the description, apply the settings, and after some seconds, the LAN interface has an IPv6 address as well as all clients in the LAN.
To me, this looks like an issue of OPNsense and not the provider. Any ideas?

Thanks in advance!

Kind regards
Kay