Some troubleshooting I did with Trent today showed: a) the "host -t soa local." call triggered a query to 127.0.0.53 as expected, network-wise, which got a response right away
b) we snapshotted ip route and ip addr just before the host call, and saw that the interface responsible for the default route (and route to his dns server) was still down. I wonder if dns_reachable() in /usr/lib/avahi/avahi-daemon-check-dns.sh is doing the right thing. It looks for 127.0.0.1 (and not 127.0.0.53), and, failing that, for a default route. The default route exists, but the link it goes through is still down: 2: eno1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN group default qlen 1000 default via x.x.x.x dev eno1 onlink linkdown -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to avahi in Ubuntu. https://bugs.launchpad.net/bugs/1752411 Title: bind9-host, avahi-daemon-check-dns.sh hang forever causes network connections to get stuck Status in avahi package in Ubuntu: Confirmed Status in bind9 package in Ubuntu: Confirmed Status in openconnect package in Ubuntu: Invalid Bug description: On 18.04 Openconnect connects successfully to any of multiple VPN concentrators but network traffic does not flow across the VPN tunnel connection. When testing on 16.04 this works flawlessly. This also worked on this system when it was on 17.10. I have tried reducing the mtu of the tun0 network device but this has not resulted in me being able to successfully ping the IP address. Example showing ping attempt to the IP of DNS server: ~$ cat /etc/resolv.conf # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8) # DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN # 127.0.0.53 is the systemd-resolved stub resolver. # run "systemd-resolve --status" to see details about the actual nameservers. nameserver 172.29.88.11 nameserver 127.0.0.53 liam@liam-lat:~$ netstat -nr Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 wlp2s0 105.27.198.106 192.168.1.1 255.255.255.255 UGH 0 0 0 wlp2s0 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0 172.17.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0 172.29.0.0 0.0.0.0 255.255.0.0 U 0 0 0 tun0 172.29.88.11 0.0.0.0 255.255.255.255 UH 0 0 0 tun0 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 wlp2s0 liam@liam-lat:~$ ping 172.29.88.11 PING 172.29.88.11 (172.29.88.11) 56(84) bytes of data. ^C --- 172.29.88.11 ping statistics --- 4 packets transmitted, 0 received, 100% packet loss, time 3054ms ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: openconnect 7.08-3 ProcVersionSignature: Ubuntu 4.15.0-10.11-generic 4.15.3 Uname: Linux 4.15.0-10-generic x86_64 ApportVersion: 2.20.8-0ubuntu10 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Wed Feb 28 22:11:33 2018 InstallationDate: Installed on 2017-06-15 (258 days ago) InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719) SourcePackage: openconnect UpgradeStatus: Upgraded to bionic on 2018-02-22 (6 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1752411/+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
