Public bug reported: It seems that when systemd-resolve cache an non-existent CNAME record for a domain, any attempt to resolve A record for the same domain fail.
systemd version the issue has been seen with Installed: 237-3ubuntu10.13 Used distribution Distributor ID: Ubuntu Description: Ubuntu 18.04.2 LTS Release: 18.04 Codename: bionic Expected behaviour you didn't see Return A record for a domain when it exists. Unexpected behaviour you saw Resolution failed. Steps to reproduce the problem Whait for 1 minutes (github.com TTL for A record) Try to resolv github.com CNAME record dig CNAME github.com This will return an empty result. Then try to resolve github.com A record dig A github.com. This will now return empty result unless you restart systemd-resolved or wait for cache expiration. At the same time using another DNS will resolve correctly dig A github.com @8.8.8.8. Exemple : Wait for 1 minutes to let cache expire, then run dig CNAME github.com dig A github.com # no result dig A github.com @8.8.8.8 # ;; ANSWER SECTION: # github.com. 59 IN A 192.30.253.113 # github.com. 59 IN A 192.30.253.112 PS: Don't forget to restart systemd-resolve, before trying to post an answer. This bug was first reported in github https://github.com/systemd/systemd/issues/11789 but systemd version in ubuntu is too old. ** Affects: systemd (Ubuntu) Importance: Undecided Status: New -- 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/1818527 Title: Stub resolver cache is corrupted Status in systemd package in Ubuntu: New Bug description: It seems that when systemd-resolve cache an non-existent CNAME record for a domain, any attempt to resolve A record for the same domain fail. systemd version the issue has been seen with Installed: 237-3ubuntu10.13 Used distribution Distributor ID: Ubuntu Description: Ubuntu 18.04.2 LTS Release: 18.04 Codename: bionic Expected behaviour you didn't see Return A record for a domain when it exists. Unexpected behaviour you saw Resolution failed. Steps to reproduce the problem Whait for 1 minutes (github.com TTL for A record) Try to resolv github.com CNAME record dig CNAME github.com This will return an empty result. Then try to resolve github.com A record dig A github.com. This will now return empty result unless you restart systemd-resolved or wait for cache expiration. At the same time using another DNS will resolve correctly dig A github.com @8.8.8.8. Exemple : Wait for 1 minutes to let cache expire, then run dig CNAME github.com dig A github.com # no result dig A github.com @8.8.8.8 # ;; ANSWER SECTION: # github.com. 59 IN A 192.30.253.113 # github.com. 59 IN A 192.30.253.112 PS: Don't forget to restart systemd-resolve, before trying to post an answer. This bug was first reported in github https://github.com/systemd/systemd/issues/11789 but systemd version in ubuntu is too old. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1818527/+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
