Checking for the state of the domain from outside a captive portal won't get much; "securelogin.arubanetworks.com" only exists while you're behind the captive portal, in unauthenticated mode.
I think the next steps will be to do some testing with various captive portals and see why systemd-resolved is unhappy with them. As far as I can tell from the provided answers, everything is in place (/etc/resolv.conf has the right values, systemd-resolved knows about the right nameservers, so some part of resolved is failing to send/receive the DNS messages in a meaningful way: this has all the hallmarks of a systemd-resolved bug. The next steps for debugging this will be to stop systemd-resolved and restart it, then attempt to resolve the domain normally (via ping, for example): sudo systemctl stop systemd-resolved sudo SYSTEMD_LOG_LEVEL=debug /lib/systemd/systemd-resolved ping securelogin.arubanetworks.com And carefully look through the logs to figure out what systemd is unhappy with. I'll do this on my end as well, but if anyone can provide the same logs, that would be very helpful. -- 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/1727237 Title: systemd-resolved is not finding a domain Status in systemd package in Ubuntu: Confirmed Bug description: I have an odd network situation that I have so far managed to narrow down to the inability to resolve a domain via systemd-resolved which is resolvable with nslookup. If I use nslookup against the two nameservers on this network I get answers for the domain, but ping says it is unable to resolve the same domain (as do browsers and crucially the captive portal mechanism). Here are details: NSLOOKUP: ~$ nslookup securelogin.arubanetworks.com 208.67.220.220 Server: 208.67.220.220 Address: 208.67.220.220#53 Non-authoritative answer: Name: securelogin.arubanetworks.com Address: 172.22.240.242 ~$ nslookup securelogin.arubanetworks.com 208.67.222.222 Server: 208.67.222.222 Address: 208.67.222.222#53 Non-authoritative answer: Name: securelogin.arubanetworks.com Address: 172.22.240.242 PING: ~$ ping securelogin.arubanetworks.com ping: securelogin.arubanetworks.com: Name or service not known mark@mark-X1Y2:~$ DIG: ~$ dig @208.67.222.222 securelogin.arubanetworks.com ; <<>> DiG 9.10.3-P4-Ubuntu <<>> @208.67.222.222 securelogin.arubanetworks.com ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 9416 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;securelogin.arubanetworks.com. IN A ;; AUTHORITY SECTION: arubanetworks.com. 1991 IN SOA dns5.arubanetworks.com. hostmaster.arubanetworks.com. 1323935888 3600 200 1209600 86400 ;; Query time: 34 msec ;; SERVER: 208.67.222.222#53(208.67.222.222) ;; WHEN: Wed Oct 25 10:31:10 CEST 2017 ;; MSG SIZE rcvd: 144 MORE DIG: ~$ dig securelogin.arubanetworks.com ; <<>> DiG 9.10.3-P4-Ubuntu <<>> securelogin.arubanetworks.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 3924 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 65494 ;; QUESTION SECTION: ;securelogin.arubanetworks.com. IN A ;; Query time: 0 msec ;; SERVER: 127.0.0.53#53(127.0.0.53) ;; WHEN: Wed Oct 25 10:34:01 CEST 2017 ;; MSG SIZE rcvd: 58 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1727237/+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
