I have the similar issue, but I'm using OpenVPN and the symptom is slightly different.
With OpenVPN, the name resolution is normal on the first attempt to connect VPN (after reboot). However, by disconnect and connect VPN again, the name resolution will be broken. As below. == Reproduce steps == 1. Reboot system 2. Connect to OpenVPN gateway 3. Issue command "host server.mydomain.com" -> success DNS request & response can be seen by sniffing (Wireshark) tun0 interface 4. Disconnect VPN 5. Connect to OpenVPN gateway 6. Issue command "host server.mydomain.com" -> Host server.mydomain.com not found: 5(REFUSED) DNS request & response can NOT be seen on tun0 nor ens33 interface Note A: After step 6, DNS resolution will NOT back to normal unless reboot or "sudo service network-manager restart". Note B: After step 6, logout and login will NOT make it back to normal. Note C: After step 6, issue command "host server.mydomain.com 192.168.3.74" -> success, assume 192.168.3.74 is the DNS server behind VPN gateway DNS request & response can be seen on tun0 interface == Package information == libnma-common 1.2.6-0ubuntu0.16.04.2 libnma0:amd64 1.2.6-0ubuntu0.16.04.2 network-manager 1.2.6-0ubuntu0.16.04.1 network-manager-gnome 1.2.6-0ubuntu0.16.04.2 network-manager-openvpn 1.1.93-1ubuntu1.1 network-manager-openvpn-gnome 1.1.93-1ubuntu1.1 network-manager-pptp 1.1.93-1ubuntu1 network-manager-pptp-gnome 1.1.93-1ubuntu1 resolvconf 1.78ubuntu4 It will became NOT reproducible after downgrading network-manager 1.2.2-0ubuntu0.16.04.3 OS version: Ubuntu Desktop 16.04.2 LTS amd64 This test is conducted under virtual machine environment to minimise uncontrollable factors. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to network-manager in Ubuntu. https://bugs.launchpad.net/bugs/1671606 Title: DNS server from vpn connection is not being used after network-manager upgrade to 1.2.6-0ubuntu0.16.04.1 Status in network-manager package in Ubuntu: Confirmed Bug description: I use my company's cisco vpn via network-manager in Ubuntu 16.04.2 LTS. After recent upgrade of network-manager:amd64 from version 1.2.2-0ubuntu0.16.04.4 to version 1.2.6-0ubuntu0.16.04.1 DNS resolution of VPN's server hostnames does not work. Roll back to version 1.2.2-0ubuntu0.16.04.4 solves the problem. Steps for reproducing: 1. upgrade network-manager:amd64 from version 1.2.2-0ubuntu0.16.04.4 to version 1.2.6-0ubuntu0.16.04.1 2. connect to VPN via network-manager applet 3. nslookop servername.internal --> ** server can't find servername.internal: NXDOMAIN 4. disconnect from VPN via network-manager applet 5. roll back network-manager via command: sudo apt-get install network-manager=1.2.2-0ubuntu0.16.04.4 6. restart network-manager via sudo service network-manager restart 7. connect to VPN via network-manager applet 8. nslookop servername.internal --> the server is resolved correctly ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: network-manager 1.2.6-0ubuntu0.16.04.1 ProcVersionSignature: Ubuntu 4.4.0-66.87-generic 4.4.44 Uname: Linux 4.4.0-66-generic x86_64 ApportVersion: 2.20.1-0ubuntu2.5 Architecture: amd64 CurrentDesktop: Unity Date: Thu Mar 9 19:49:55 2017 InstallationDate: Installed on 2015-10-05 (520 days ago) InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422) NetworkManager.state: [main] NetworkingEnabled=true WirelessEnabled=true WWANEnabled=true WimaxEnabled=true SourcePackage: network-manager UpgradeStatus: No upgrade log present (probably fresh install) nmcli-nm: RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN running 1.2.6 connected started full enabled enabled enabled enabled enabled To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1671606/+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
