It's happened to me a few times on 20.04.1: $ host support.coinjar.com support.coinjar.com has address 0.0.0.0 support.coinjar.com has IPv6 address :: support.coinjar.com is an alias for coinjar.zendesk.com. coinjar.zendesk.com mail is handled by 10 mail-pod-25.int.zendesk.com. $ sudo resolvectl flush-caches
$ host support.coinjar.com support.coinjar.com has address 0.0.0.0 support.coinjar.com has IPv6 address :: support.coinjar.com is an alias for coinjar.zendesk.com. coinjar.zendesk.com mail is handled by 10 mail-pod-25.int.zendesk.com. $ dig support.coinjar.com ; <<>> DiG 9.16.1-Ubuntu <<>> support.coinjar.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 12759 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 65494 ;; QUESTION SECTION: ;support.coinjar.com. IN A ;; ANSWER SECTION: support.coinjar.com. 34 IN A 0.0.0.0 ;; Query time: 0 msec ;; SERVER: 127.0.0.53#53(127.0.0.53) ;; WHEN: Wed Jan 06 20:23:28 AEDT 2021 ;; MSG SIZE rcvd: 64 Then 2 minutes later the problem resolves itself: $ dig support.coinjar.com ; <<>> DiG 9.16.1-Ubuntu <<>> support.coinjar.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 64605 ;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 65494 ;; QUESTION SECTION: ;support.coinjar.com. IN A ;; ANSWER SECTION: support.coinjar.com. 151 IN CNAME coinjar.zendesk.com. coinjar.zendesk.com. 900 IN A 104.16.51.111 coinjar.zendesk.com. 900 IN A 104.16.53.111 ;; Query time: 68 msec ;; SERVER: 127.0.0.53#53(127.0.0.53) ;; WHEN: Wed Jan 06 20:25:31 AEDT 2021 ;; MSG SIZE rcvd: 110 Nothing in /var/log/syslog or systemd-resolved's systemd log. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1170353 Title: Host names intermittently resolve to 0.0.0.0 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1170353/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs