On 12 October 2017 at 14:55, Matthias Fratz <1714...@bugs.launchpad.net> wrote: > As for ubuntu.com, that was only as an example to show a situations when > things break. I really just copied what the original submitter used -- I > should probably have used example.com instead though, that's less > confusing. > > My concrete situation is that the server delivers only inf.uni- > konstanz.de because that's what matches the university's organizational > structure. (And having it changed it is not an option.) I put the other > two (disy.inf.uni-konstanz.de and uni-konstanz.de) in the search path > long ago because I regularly connect to hosts in those domains. Saves a > lot of typing errors, and AFAIK it's not an uncommon use case for the > search path. But this broke DNS resolution for disy.inf.uni-konstanz.de > and uni-konstanz.de (probably because they're not in any per-interface > search path) on upgrade to 17.04, and got me to this bug. > > As far as I can tell now, the bug should only affect users on or > upgrading to zesty who have manually configured a search path using > resolvconf, and artful users who configure one in resolved.conf. That's > clearly a minority of users. > > I certainly agree to the "only send queries to the right nameserver" > part. That makes sense, as does UseDomains and setting it to true by > default. What I find troubling is that it seems to just swallow the > query when there's no interface matching a search path entry. That > doesn't agree with the documentation of either Domains= or UseDomains=, > which both suggest that one can have search paths not associated with an > interface. But I guess that's a bug in the systemd-resolved and not in > Ubuntu, so I'll probably just report it upstream. >
I'd rather report the bug upstream myself, as upstream prefer downstream distributions to curate these things. Clearly, as an end-user you cannot fix DHCP server config if it provides insufficient search paths. So you are saying that you have a.example.com domain configured on the link, with a nameserver W.X.Y.Z which can also resolve b.example.com domains and you want it to do so, and when setting Domains in resolved.conf it does not result in resolving b.example.com domains in addition to a.example.com domains? I'm not sure if this is a bug or a feature =)))))) The right answer is probably to have per-link configuration encoded in netplan/networkd/networkmanager, but that might be annoying to do if one connects to said network over wifi, over usb ethernet on different usb ports, and multiple vlan end-points. As I guess on such a network all of these connections are valid, and all of them will receive incomplete search list and it would be convenient to set a global list. I'll play around with this. -- Regards, Dimitri. -- 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/1714803 Title: Search list in resolv.conf breaks resolving for that domain Status in systemd package in Ubuntu: Incomplete Bug description: Ubuntu 17.04 systemd 232-21ubuntu5 Adding a domain to the search list in /etc/resolv.conf breaks resolving for that domain. Not only does the search list not get used as expected, but host names in the domain cannot be resolved by systemd-resolved at all. I just ran into this after upgrading from ubuntu 16.04 to 17.04 which enabled systemd-resolved. I have for a long time used resolveconf to add a 'search my-domain'-line to my /etc/resolv.conf. Example of expected behaviour. With Googles DNS server (8.8.8.8) and ubuntu.com in the search list in /etc/resolv.conf. Both dig and systemd-resolve can resolve www.ubuntu.com and www: $ cat /etc/resolv.conf nameserver 8.8.8.8 search ubuntu.com $ dig +nostat +nocmd www.ubuntu.com ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 55037 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 512 ;; QUESTION SECTION: ;www.ubuntu.com. IN A ;; ANSWER SECTION: www.ubuntu.com. 501 IN A 91.189.89.115 $ dig +search +nostat +nocmd www ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 25772 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 512 ;; QUESTION SECTION: ;www.ubuntu.com. IN A ;; ANSWER SECTION: www.ubuntu.com. 382 IN A 91.189.89.103 $ systemd-resolve www.ubuntu.com www.ubuntu.com: 91.189.89.115 -- Information acquired via protocol DNS in 2.7ms. -- Data is authenticated: no $ systemd-resolve www www: 91.189.90.59 (www.ubuntu.com) -- Information acquired via protocol DNS in 3.8ms. -- Data is authenticated: no Ubuntu 17.04 default config, with the systemd-resolved name server in /etc/resolv.conf and no search list. www.ubuntu.com can still be resolved correctly: $ cat /etc/resolv.conf nameserver 127.0.0.53 $ dig +nostat +nocmd www.ubuntu.com ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 64646 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 65494 ;; QUESTION SECTION: ;www.ubuntu.com. IN A ;; ANSWER SECTION: www.ubuntu.com. 482 IN A 91.189.89.110 $ systemd-resolve www.ubuntu.com www.ubuntu.com: 91.189.90.58 -- Information acquired via protocol DNS in 18.2ms. -- Data is authenticated: no Broken behaviour, using the systemd-resolved name server and specify ubuntu.com in search list. Resolving fails for www.ubuntu.com and www, both using dig (DNS) and using sytemd-resolve: $ cat /etc/resolv.conf nameserver 127.0.0.53 search ubuntu.com $ dig +nostat +nocmd www.ubuntu.com ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 33334 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 65494 ;; QUESTION SECTION: ;www.ubuntu.com. IN A $ dig +search +nostat +nocmd www ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 50588 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 65494 ;; QUESTION SECTION: ;www.ubuntu.com. IN A $ systemd-resolve www.ubuntu.com www.ubuntu.com: resolve call failed: No appropriate name servers or networks for name found $ systemd-resolve www www: resolve call failed: All attempts to contact name servers or networks failed To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1714803/+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
