Public bug reported: Since upgrading to 17.10, hostname resolution (via, e.g., Firefox or the "host" command-line tool) does not work reliably anymore. Once hostname resolution fails (Firefox 57: "Hmm. We're having trouble finding that site."), manually resolving the host via "systemd-resolve" succeeds and temporarily allows Firefox to also resolve that host. After a few minutes, resolution of the same host fails again.
Example with command-line "host" utility: $ host www.heise.de ;; connection timed out; no servers could be reached $ cat /etc/resolv.conf # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8) # DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN # 127.0.0.53 is the systemd-resolved stub resolver. # run "systemd-resolve --status" to see details about the actual nameservers. nameserver 127.0.0.53 search fritz.box $ systemd-resolve www.heise.de www.heise.de: 2a02:2e0:3fe:1001:7777:772e:2:85 193.99.144.85 -- Information acquired via protocol DNS in 273.2ms. -- Data is authenticated: no $ host www.heise.de www.heise.de has address 193.99.144.85 www.heise.de has IPv6 address 2a02:2e0:3fe:1001:7777:772e:2:85 $ systemd-resolve --status Global DNS Servers: 192.168.178.1 DNS Domain: fritz.box 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 4 (wlp3s0) Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6 LLMNR setting: yes MulticastDNS setting: no DNSSEC setting: no DNSSEC supported: no DNS Servers: fd00::cece:1eff:fe61:2ece Link 3 (enp0s20f0u5c2) Current Scopes: none LLMNR setting: yes MulticastDNS setting: no DNSSEC setting: no DNSSEC supported: no Link 2 (enp0s31f6) Current Scopes: none LLMNR setting: yes MulticastDNS setting: no DNSSEC setting: no DNSSEC supported: no [... wait 2-3 minutes ...] $ host www.heise.de ;; connection timed out; no servers could be reached $ systemd-resolve www.heise.de www.heise.de: 2a02:2e0:3fe:1001:7777:772e:2:85 193.99.144.85 -- Information acquired via protocol DNS in 284.2ms. -- Data is authenticated: no $ host www.heise.de www.heise.de has address 193.99.144.85 www.heise.de has IPv6 address 2a02:2e0:3fe:1001:7777:772e:2:85 ProblemType: Bug DistroRelease: Ubuntu 17.10 Package: systemd 234-2ubuntu12.1 ProcVersionSignature: Ubuntu 4.13.0-16.19-generic 4.13.4 Uname: Linux 4.13.0-16-generic x86_64 ApportVersion: 2.20.7-0ubuntu3.4 Architecture: amd64 CurrentDesktop: KDE Date: Sat Nov 18 19:32:56 2017 InstallationDate: Installed on 2016-11-26 (357 days ago) InstallationMedia: Kubuntu 16.10 "Yakkety Yak" - Release amd64 (20161012.1) MachineType: LENOVO 20FXS05500 ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.13.0-16-generic root=/dev/mapper/vgubuntu-root ro kopt=root=/dev/mapper/vgubuntu-root SourcePackage: systemd UpgradeStatus: Upgraded to artful on 2017-10-21 (28 days ago) dmi.bios.date: 09/04/2017 dmi.bios.vendor: LENOVO dmi.bios.version: R07ET79W (2.19 ) dmi.board.asset.tag: Not Available dmi.board.name: 20FXS05500 dmi.board.vendor: LENOVO dmi.board.version: Not Defined dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: None dmi.modalias: dmi:bvnLENOVO:bvrR07ET79W(2.19):bd09/04/2017:svnLENOVO:pn20FXS05500:pvrThinkPadT460p:rvnLENOVO:rn20FXS05500:rvrNotDefined:cvnLENOVO:ct10:cvrNone: dmi.product.family: ThinkPad T460p dmi.product.name: 20FXS05500 dmi.product.version: ThinkPad T460p dmi.sys.vendor: LENOVO ** Affects: systemd (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug artful -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1733103 Title: DNS hostname resolution fails intermittently Status in systemd package in Ubuntu: New Bug description: Since upgrading to 17.10, hostname resolution (via, e.g., Firefox or the "host" command-line tool) does not work reliably anymore. Once hostname resolution fails (Firefox 57: "Hmm. We're having trouble finding that site."), manually resolving the host via "systemd- resolve" succeeds and temporarily allows Firefox to also resolve that host. After a few minutes, resolution of the same host fails again. Example with command-line "host" utility: $ host www.heise.de ;; connection timed out; no servers could be reached $ cat /etc/resolv.conf # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8) # DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN # 127.0.0.53 is the systemd-resolved stub resolver. # run "systemd-resolve --status" to see details about the actual nameservers. nameserver 127.0.0.53 search fritz.box $ systemd-resolve www.heise.de www.heise.de: 2a02:2e0:3fe:1001:7777:772e:2:85 193.99.144.85 -- Information acquired via protocol DNS in 273.2ms. -- Data is authenticated: no $ host www.heise.de www.heise.de has address 193.99.144.85 www.heise.de has IPv6 address 2a02:2e0:3fe:1001:7777:772e:2:85 $ systemd-resolve --status Global DNS Servers: 192.168.178.1 DNS Domain: fritz.box 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 4 (wlp3s0) Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6 LLMNR setting: yes MulticastDNS setting: no DNSSEC setting: no DNSSEC supported: no DNS Servers: fd00::cece:1eff:fe61:2ece Link 3 (enp0s20f0u5c2) Current Scopes: none LLMNR setting: yes MulticastDNS setting: no DNSSEC setting: no DNSSEC supported: no Link 2 (enp0s31f6) Current Scopes: none LLMNR setting: yes MulticastDNS setting: no DNSSEC setting: no DNSSEC supported: no [... wait 2-3 minutes ...] $ host www.heise.de ;; connection timed out; no servers could be reached $ systemd-resolve www.heise.de www.heise.de: 2a02:2e0:3fe:1001:7777:772e:2:85 193.99.144.85 -- Information acquired via protocol DNS in 284.2ms. -- Data is authenticated: no $ host www.heise.de www.heise.de has address 193.99.144.85 www.heise.de has IPv6 address 2a02:2e0:3fe:1001:7777:772e:2:85 ProblemType: Bug DistroRelease: Ubuntu 17.10 Package: systemd 234-2ubuntu12.1 ProcVersionSignature: Ubuntu 4.13.0-16.19-generic 4.13.4 Uname: Linux 4.13.0-16-generic x86_64 ApportVersion: 2.20.7-0ubuntu3.4 Architecture: amd64 CurrentDesktop: KDE Date: Sat Nov 18 19:32:56 2017 InstallationDate: Installed on 2016-11-26 (357 days ago) InstallationMedia: Kubuntu 16.10 "Yakkety Yak" - Release amd64 (20161012.1) MachineType: LENOVO 20FXS05500 ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.13.0-16-generic root=/dev/mapper/vgubuntu-root ro kopt=root=/dev/mapper/vgubuntu-root SourcePackage: systemd UpgradeStatus: Upgraded to artful on 2017-10-21 (28 days ago) dmi.bios.date: 09/04/2017 dmi.bios.vendor: LENOVO dmi.bios.version: R07ET79W (2.19 ) dmi.board.asset.tag: Not Available dmi.board.name: 20FXS05500 dmi.board.vendor: LENOVO dmi.board.version: Not Defined dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: None dmi.modalias: dmi:bvnLENOVO:bvrR07ET79W(2.19):bd09/04/2017:svnLENOVO:pn20FXS05500:pvrThinkPadT460p:rvnLENOVO:rn20FXS05500:rvrNotDefined:cvnLENOVO:ct10:cvrNone: dmi.product.family: ThinkPad T460p dmi.product.name: 20FXS05500 dmi.product.version: ThinkPad T460p dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1733103/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp