I've got a local server (192.168.0.10) running dnsmasq to provide DHCP for my LAN, and a DNS server to resolve hostnames for the DHCP clients.
When I was running 16.04, this worked fine. Any machine getting a DHCP address from the server used the DNS server, and could resolve other hostnames on the network.
However, since upgrading to 18.04, I can't resolve hostnames any more. I understand that 18.04 now uses systemd-resolve. It appears that it's aware of the DNS server:
mark@coachz:~$ systemd-resolve --status Global DNSSEC NTA: 10.in-addr.arpa 16.172.in-addr.arpa 168.192.in-addr.arpa 17.172.in-addr.arpa 18.172.in-addr.arpa 19.172.in-addr.arpa 20.172.in-addr.arpa 21.172.in-addr.arpa 22.172.in-addr.arpa 23.172.in-addr.arpa 24.172.in-addr.arpa 25.172.in-addr.arpa 26.172.in-addr.arpa 27.172.in-addr.arpa 28.172.in-addr.arpa 29.172.in-addr.arpa 30.172.in-addr.arpa 31.172.in-addr.arpa corp d.f.ip6.arpa home internal intranet lan local private test Link 3 (wlp59s0) Current Scopes: DNS LLMNR setting: yes MulticastDNS setting: no DNSSEC setting: no DNSSEC supported: no DNS Servers: 192.168.0.10 Link 2 (enp58s0f1) Current Scopes: none LLMNR setting: yes MulticastDNS setting: no DNSSEC setting: no DNSSEC supported: no
However, it doesn't seem to use it to resolve hostnames:
mark@coachz:~$ nslookup homestar Server: 127.0.0.53 Address: 127.0.0.53#53 ** server can't find homestar: SERVFAIL
Although if I explicitly tell it to, it can:
mark@coachz:~$ nslookup homestar 192.168.0.10 Server: 192.168.0.10 Address: 192.168.0.10#53 Name: homestar Address: 192.168.0.101
How do I get it to use the DHCP-provided DNS server automatically?