systemd-resolve appends "options edns0" to resolv.conf
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
resolvconf (Ubuntu) |
Fix Released
|
Critical
|
Dan Streetman | ||
Bionic |
Fix Released
|
Critical
|
Dan Streetman | ||
Cosmic |
Fix Released
|
Critical
|
Dan Streetman | ||
Disco |
Fix Released
|
Critical
|
Dan Streetman |
Bug Description
[impact]
systems upgraded from pre-Bionic releases to Bionic or later will continue to use ifupdown/resolvconf for network conf and management, but resolvconf has a new systemd service in Bionic and later that pulls systemd-resolved stub-resolv.conf into its local configuration. With the recent addition of edns0 option to the stub resolver conf in systemd to fix bug 1811471, this means resolvconf now sets up the /etc/resolv.conf file to include upstream servers but also use edns. For any systems where the upstream resolver(s) don't support edns, dns lookups will break.
[test case]
== upgrade from pre-bionic (e.g. xenial) to bionic or later ==
1) create a xenial system with ifupdown/
2) upgrade the system to bionic (alternately it should be possible to install bionic, then remove netplan and install/configure ifupdown and resolvconf, but I have not specifically tested this). The upgrade will retain the ifupdown/resolvconf configuration, and will not change to netplan/
a) the upstream name server(s)
b) options edns0
c) the local stub resolver (127.0.0.53)
d) search domain
the fixed resolvconf will remove (b).
As mentioned, this case also should cover the situation of a native Bionic install, where netplan is removed and ifupdown/resolvconf is manually installed.
== bionic or later install ==
with a bionic install, ifupdown is not installed, instead netplan/
If resolvconf is installed while systemd-networkd is managing the network, then currently the resolv.conf contents will remain completely unchanged, still pointing to the local stub resolver.
This resolvconf change will alter that, to remove 'options edns0'. No other changes will be made from the stub-resolv.conf.
[regression potential]
Regressions due to this change would likely be seen in dns query failures with other system configurations.
This will cause systems with resolvconf installed to lose the fix from bug 1811471, and again experience that bug.
[other info]
This affects only Bionic and later; in Xenial and earlier, systemd does not handle dns, and the 'edns0' option was not added to that systemd-resolved anyway.
This also does not affect Debian, as it does not include the 'resolvconf-
original description:
--
Mint 19 (Ubuntu 18.04)
Following latest mint update done on 24/02/2019, DNS is broken....
nslookup and dig of certain domain names work as expected, ping does not (ip works but not domain name)
After a day of trial and error, testing I found that the problem lies with the presence of
"options edns0"
in /run/resolvconf
With option present many dns lookups fail with both FF and chrome browswers and thunderbird...
This is on a home network, with router set as dns proxy for external wan, not using NetworkManager
Deleting the option on live system results in the issue immediately disappearing, but on reboot it is added back in (by systemd-resolve ?)
I cannot find any option to prevent this being added, so presumably it is hard-coded in systemd following the update?
systemd:
Installed: 237-3ubuntu10.13
description: | updated |
Changed in systemd (Ubuntu Trusty): | |
status: | New → Invalid |
Changed in systemd (Ubuntu Xenial): | |
status: | New → Invalid |
Changed in systemd (Ubuntu Bionic): | |
status: | New → In Progress |
Changed in systemd (Ubuntu Cosmic): | |
status: | New → In Progress |
importance: | Undecided → Critical |
Changed in systemd (Ubuntu Bionic): | |
importance: | Undecided → Critical |
Changed in systemd (Ubuntu Cosmic): | |
assignee: | nobody → Dan Streetman (ddstreet) |
Changed in systemd (Ubuntu Bionic): | |
assignee: | nobody → Dan Streetman (ddstreet) |
Changed in resolvconf (Ubuntu Disco): | |
assignee: | nobody → Dan Streetman (ddstreet) |
importance: | Undecided → High |
status: | New → In Progress |
importance: | High → Critical |
Changed in systemd (Ubuntu Bionic): | |
status: | In Progress → Invalid |
Changed in systemd (Ubuntu Cosmic): | |
status: | In Progress → Invalid |
Changed in systemd (Ubuntu Disco): | |
status: | In Progress → Invalid |
Changed in systemd (Ubuntu Bionic): | |
assignee: | Dan Streetman (ddstreet) → nobody |
importance: | Critical → Undecided |
Changed in systemd (Ubuntu Cosmic): | |
assignee: | Dan Streetman (ddstreet) → nobody |
importance: | Critical → Undecided |
Changed in systemd (Ubuntu Disco): | |
assignee: | Dan Streetman (ddstreet) → nobody |
importance: | Critical → Undecided |
Changed in resolvconf (Ubuntu Cosmic): | |
assignee: | nobody → Dan Streetman (ddstreet) |
importance: | Undecided → Critical |
status: | New → In Progress |
Changed in resolvconf (Ubuntu Bionic): | |
assignee: | nobody → Dan Streetman (ddstreet) |
importance: | Undecided → Critical |
status: | New → In Progress |
Changed in resolvconf (Ubuntu Xenial): | |
status: | New → Invalid |
Changed in resolvconf (Ubuntu Trusty): | |
status: | New → Invalid |
description: | updated |
description: | updated |
Changed in resolvconf (Ubuntu Cosmic): | |
status: | Triaged → In Progress |
Changed in resolvconf (Ubuntu Bionic): | |
status: | Triaged → In Progress |
Changed in resolvconf (Ubuntu Disco): | |
status: | Fix Released → In Progress |
tags: | added: patch |
description: | updated |
tags: | removed: verification-done verification-done-bionic verification-done-cosmic |
Changed in resolvconf (Ubuntu Disco): | |
status: | Fix Committed → Fix Released |
no longer affects: | resolvconf (Ubuntu Trusty) |
no longer affects: | resolvconf (Ubuntu Xenial) |
no longer affects: | systemd (Ubuntu Trusty) |
no longer affects: | systemd (Ubuntu Xenial) |
no longer affects: | systemd (Ubuntu) |
no longer affects: | systemd (Ubuntu Cosmic) |
no longer affects: | systemd (Ubuntu Bionic) |
no longer affects: | systemd (Ubuntu Disco) |
Thank you for your bug report, did you try to downgrading the system packages to see if that resolves the issue? /bugs.launchpad .net/ubuntu/ +source/ systemd/ 237-3ubuntu10. 12
The previous update has change in dns queries
https:/
Would be interesting to know if that version already had the problem?