On 15/09/18 10:05, Andrey Vakhitov wrote: > Hello Uwe, > >>> My recommendation to the reporter: >>> - Don't use stateful DHCPv6 in Germany, that does not work well. You >>> clients should get the addresses using router advertisements. For static > hosts assign static names in your own domain. The "ra-names" >>> assigns both the IPv4 and IPv6 address to the SLAAC name, so lookup >>> works fine. With router advertisements, DNSmasq will send "deprecated" > >> As you correctly recognized, the reason for usage of stateful DHCPv6 was > to get correct dynamic name resolution for IPv6. >> I also see the combination of DHCPv4 with SLAAC as possible workaround, > I've to try it > > I've set it up as you suggested, initially name resolution seems to work > fine. But after some days of operation (and some nightly reconnects) dnsmasq > seems to loose associated IPv6 adresses: DNS request reports only IPv6 > address assigned via DHCP. The SLAAC-based IPv6 addresses on hosts are > present and correct. How can I investigate and fix this issue?
Hmm, not easy. Look in the log for lines that look like DHCPv4-derived IPv6 names on ........ which should occur after a reconnect with a different address which causes new DHCP address ranges to be constructed. After that happens, dnsmasq will take a guess at the IPv6 addresses that hosts will assign themselves, based on the network address and the MAC address of the host (transformed into EUI-64) It then starts to ping those addresses, and when it gets a reply, it will log SLAAC_CONFIRM(interface) <address> <hostname> and start using the address/name in the DNS. Once confirmed, the addresses remain valid until the DHCPv4 lease it's based on expires or goes though init-reboot state or the MAC address or interface it's accessible by changes. The only other thing that will delete these addresses in a new address appearing and a new dhcp range being created, hence it's interesting to look at what happens in the logs after each of those events. Cheers, Simon. > > Best regards, > -- > Andrey Vakhitov > > E-Mail: and...@vakhitov.net Stuttgart, Germany > > > > > _______________________________________________ > Dnsmasq-discuss mailing list > Dnsmasqemail@example.com > http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss > > > _______________________________________________ > Dnsmasq-discuss mailing list > Dnsmasqfirstname.lastname@example.org > http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss > _______________________________________________ Dnsmasq-discuss mailing list Dnsmasqemail@example.com http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss