So I managed to reproduce this in a way that looks correct (Starbucks WiFi here uses Datavalet but fails in a way that looks the same: it thinks you're logged in once you clicked the "Login" button on the captive portal page once, but then updates DNS, but still attempts to look up secure.datavalet.io (but this is no longer resolving because we're in the public side now); and once you try to hit another site, you did not get to the "landing" page on the public side so it thinks you're still unauthenticated.
One one hand, this looks like just really terrible behavior of the captive portal, and it "worked" only because we were pretty slow to deal with the changing settings; or because we were caching the DNS responses for just long enough. I got logs from my reproducer as well as packet captures, and I will have to comb through them to figure out if there's anything really obscure and wrong, but my initial guess is that this is an issue related to DNS caching. Probably the cache is invalidated when the IP changes as we get to the public side, but ought to retain the resolution address for the portal. It needs a little more investigation and testing, but I think this qualifies as "Triaged" now; and should have some fix or workaround to deal with Aruba and Datavalet, both are reasonably common hotspot infrastructure. ** Changed in: systemd (Ubuntu) Status: Confirmed => Triaged ** Changed in: systemd (Ubuntu) Importance: Undecided => High -- 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: Triaged 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