Ok. So I gave the router's dhcp service another chance (basic install), with/without IPv6 enabled on .246.20 & .260 and it's a no-go.
With DAP (DNSSEC)/DNSMASQ enabled on the NAS and the router's dhcp services disabled:
Having inconsistent test results is considered as a failure.
Cheers
Terminal:~ root# nslookup
> vault
Server: 10.0.0.1
Address: 10.0.0.1#53
** server can't find vault: NXDOMAIN
> vault.maison.lan
Server: 10.0.0.1
Address: 10.0.0.1#53
** server can't find vault.maison.lan: NXDOMAIN
> ^C
Terminal:~ root# ping vault
ping: cannot resolve vault: Unknown host
Terminal:~ root# ping vault.maison.lan
ping: cannot resolve vault.maison.lan: Unknown host
Terminal:~ root# ping gateway
PING gateway.maison.lan (10.0.0.1): 56 data bytes
64 bytes from 10.0.0.1: icmp_seq=0 ttl=64 time=0.919 ms
64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=0.946 ms
^C
--- gateway.maison.lan ping statistics ---
2 packets transmitted, 2 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.919/0.932/0.946/0.013 ms
Terminal:~ root#
With DAP (DNSSEC)/DNSMASQ enabled on the NAS and the router's dhcp services disabled:
Terminal:~ root# nslookup
> vault
Server: 10.0.0.10
Address: 10.0.0.10#53
Non-authoritative answer:
Name: vault.maison.lan
Address: 10.0.0.10
> vault.maison.lan
Server: 10.0.0.10
Address: 10.0.0.10#53
Non-authoritative answer:
Name: vault.maison.lan
Address: 10.0.0.10
>
Having inconsistent test results is considered as a failure.
Cheers