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 Desktop Packages, which is subscribed to network-manager in Ubuntu. https://bugs.launchpad.net/bugs/1170353 Title: Host names intermittently resolve to 0.0.0.0 Status in network-manager package in Ubuntu: Invalid Bug description: About 5% of DNS queries resolve to 0.0.0.0. A couple of times an hour during normal browsing, Firefox resolves a domain to 0.0.0.0. Opening the same site in Chrome has a 50% chance of it working, then it normally works after a few reloads. Thunderbird has also occasionally resolved googlemail.com to 0.0.0.0. Domains include google.com, wikipedia.org, harvestapp.com and many more. I couldn't reproduce this with dig/nslookup for a while, but after 5 minutes of (re)trying random domains) did: $ dig mail.google.com ; <<>> DiG 9.8.1-P1 <<>> mail.google.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 22905 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;mail.google.com. IN A ;; ANSWER SECTION: mail.google.com. 60 IN A 0.0.0.0 ;; Query time: 0 msec ;; SERVER: 127.0.1.1#53(127.0.1.1) ;; WHEN: Thu Apr 18 13:57:04 2013 ;; MSG SIZE rcvd: 49 Note the "0 msec", so I'm pretty sure this is dnsmasq's local cache. Using Xubuntu 12.10, NetworkManager 0.9.6.0, Dnsmasq 2.63rc6. NetworkManager has DNS servers set to "8.8.8.8, 8.8.4.4" (also tried setting it to my router's DNS server, with no effect). /etc/resolve.conf just has "nameserver 127.0.1.1" dnsmasq is currently running: /usr/sbin/dnsmasq --no-resolv --keep-in-foreground --no-hosts --bind- interfaces --pid-file=/var/run/sendsigs.omit.d/network- manager.dnsmasq.pid --listen-address=127.0.1.1 --conf-file=/var/run /nm-dns-dnsmasq.conf --cache-size=0 --proxy-dnssec --enable- dbus=org.freedesktop.NetworkManager.dnsmasq --conf- dir=/etc/NetworkManager/dnsmasq.d ProblemType: Bug DistroRelease: Ubuntu 12.10 Package: network-manager 0.9.6.0-0ubuntu7 ProcVersionSignature: Ubuntu 3.5.0-21.32-generic 3.5.7.1 Uname: Linux 3.5.0-21-generic x86_64 NonfreeKernelModules: nvidia ApportVersion: 2.6.1-0ubuntu10 Architecture: amd64 CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found. Date: Thu Apr 18 14:27:33 2013 IfupdownConfig: # interfaces(5) file used by ifup(8) and ifdown(8) auto lo iface lo inet loopback InstallationDate: Installed on 2013-01-11 (97 days ago) InstallationMedia: Xubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.1) IpRoute: default via 10.0.0.1 dev eth0 proto static 10.0.0.0/24 dev eth0 proto kernel scope link src 10.0.0.10 metric 1 169.254.0.0/16 dev eth0 scope link metric 1000 IwConfig: eth0 no wireless extensions. lo no wireless extensions. MarkForUpload: True NetworkManager.state: [main] NetworkingEnabled=true WirelessEnabled=true WWANEnabled=true WimaxEnabled=true RfKill: SourcePackage: network-manager UpgradeStatus: No upgrade log present (probably fresh install) WifiSyslog: Apr 18 09:48:24 base100 kernel: [ 3679.586853] xhci_hcd 0000:00:14.0: WARN Event TRB for slot 1 ep 0 with no TDs queued? Apr 18 10:09:03 base100 kernel: [ 4916.445925] xhci_queue_intr_tx: 39 callbacks suppressed Apr 18 10:09:06 base100 kernel: [ 4919.096387] xhci_hcd 0000:00:14.0: WARN Event TRB for slot 1 ep 0 with no TDs queued? Apr 18 13:50:09 base100 kernel: [18155.501321] xhci_hcd 0000:00:14.0: WARN Event TRB for slot 1 ep 0 with no TDs queued? mtime.conffile..etc.NetworkManager.NetworkManager.conf: 2013-01-11T14:15:17.434186 nmcli-con: NAME UUID TYPE TIMESTAMP TIMESTAMP-REAL AUTOCONNECT READONLY DBUS-PATH YB SmarTrack 71694158-7304-4ff6-9092-7cc19e22acf4 vpn 1366020364 Mon 15 Apr 2013 11:06:04 BST no no /org/freedesktop/NetworkManager/Settings/1 Wired connection 1 81386800-1e66-4f17-88d3-37233ab45958 802-3-ethernet 1366291620 Thu 18 Apr 2013 14:27:00 BST yes no /org/freedesktop/NetworkManager/Settings/0 nmcli-dev: DEVICE TYPE STATE DBUS-PATH eth0 802-3-ethernet connected /org/freedesktop/NetworkManager/Devices/0 nmcli-nm: RUNNING VERSION STATE NET-ENABLED WIFI-HARDWARE WIFI WWAN-HARDWARE WWAN running 0.9.6.0 connected enabled enabled enabled enabled disabled To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1170353/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp