[09:25] <Devil_Kin> JanC: went through the feature list, and yeah couldn't directly spot any in the 2.1 release. ZFS 2.0 was a different beast 
[13:55] <jafa2> hi guys, netplan dhcp6:yes doesn't seem to result in getting a ipv6 address from the isp... manually running dhclient -6 gets an ip
[13:56] <jafa2> the interfaces does get an ipv6 link local as expected
[13:59] <jafa2> is there something I need to configure in netplan or dhclient so the system picks up the ipv6 address automatically?
[14:21] <tomreyn> did you read the description of the dhcp6 option at https://netplan.io/reference/#common-properties-for-all-device-types ?
[14:21] <tomreyn> i'm not sure that any of this is causing it, but dhcp6 is definitely more complex than just dhcp4, due to more options.
[14:22] <tomreyn> which netplan renderer you're using can also matter (and you haven't told us)
[14:22] <tomreyn> jafa2: ^
[14:40] <jafa2> hi tomreyn, not seeing anything interesting in the dhcp overrides documentation. Not specifying the renderer (ubuntu server 20.04) and I haven't figured out how to get netplan to tell me
[14:41] <jafa2> can I read back from netplan which renderer it is using?
[14:42] <tomreyn> i'm not aware of where this is stated, if anywhere, but i believe the default renderer is systemd-networkd
[14:43] <tomreyn> i wasn't thinking of dhcp overrides, just of statements such as "Autoconfiguration will still honour the contents of the router advertisement
[14:43] <tomreyn> and only use DHCP if requested in the RA."
[14:44] <tomreyn> if you look in /run/ you should see either a systemd-networkd or netplan configuration for this interface, i think
[14:48] <jafa2> seeing things under /run/systemd/network/
[14:50] <jafa2> 10-netplan-wan.network shows DHCP=yes LinkLocalAddressing=ipv6 and some not-interesitng DHCP options
[14:55] <jafa2> i can put dhclient -6 in rc.local but it seems like something netplan should be handling
[15:54] <frickler> jafa2: check with tcpdump whether you are getting RAs from your isp. if not, dhcp6 will not be of much use to you anyway, as you will only have an address, but no router
[17:32] <jafa2> tcpdump.... checking
[17:33] <jafa2> after doing a dhclient -6 I get a /128 address (the 'every sperm is precious' school of ipv6 addressing) and the server has ipv6 internet access
[17:35] <jafa2> getting "ip6-allnodes: ICMP6, router advertisement, length 32"
[17:38] <jafa2> the RA contains a cisco link layer address - seems pretty normal
[17:40] <jafa2> oh, hang on...
[17:47] <jafa2> working!
[17:48] <jafa2> the DHCP advertise was being blocked by ip6tables...
[17:48] <jafa2> guess conntrack isn't tracking it
[17:50] <jafa2> reboot - everything came up nicely
[18:01] <jafa2> because the ISP is only handling out a single ipv6 /128 address I created an ip6tables postrouting masquerade rule and a forward contrack rule so other devices on the lan can route through this server. However when a device attempts to send ipv6 the server sends back an ICMP Destination Unreachable (Beyond the scope of source address) error
[18:31] <jafa2> playing around with trying to request a /64
[21:04] <kenyon> jafa2: you use DHCPv6 Prefix Delegation to get a routed subnet. the /128 is normal and typical for the WAN link.
[21:04] <kenyon> jafa2: see also #IPv6 here on Libera.Chat
[23:07] <jafa2> kenyon - thanks