Created attachment 1450794 [details] From syslog Description of problem: Sometimes I can see my network is not available. When I have a look at syslog, I see that unbound has crashed. Version-Release number of selected component (if applicable): unbound-1.7.1-1.fc28.x86_64 How reproducible: very rarely Steps to Reproduce: 1. unclear Actual results: Resolving DNS addresses no longer works. Pinging well-known public IP addresses still works fine. See syslog attached for details. Expected results: Resolving DNS addresses should work fine Additional info: There is no crash reported to coredumpctl so I cannot use that one to get you a backtrace, sorry. Is this caused by unbound itself? If yes, it would be good to have unbound behave as any other application and leave us a coredump to hunt down bugs.
Same here with unbound-1.7.2-1.fc28.x86_64: Jun 20 13:16:16 systemd[1]: Starting Unbound recursive Domain Name Server... Jun 20 13:16:16 unbound-checkconf[1218]: unbound-checkconf: no errors in /etc/unbound/unbound.conf Jun 20 13:16:16 systemd[1]: Started Unbound recursive Domain Name Server. Jun 20 13:16:16 unbound[1248]: [1248:0] notice: init module 0: ipsecmod Jun 20 13:16:16 unbound[1248]: [1248:0] notice: init module 1: validator Jun 20 13:16:16 unbound[1248]: [1248:0] notice: init module 2: iterator Jun 20 13:16:16 unbound[1248]: [1248:0] info: start of service (unbound 1.7.2). Jun 20 13:16:16 unbound[1248]: [1248:0] error: .: failed lookup, cannot probe to master k.root-servers.net Jun 20 13:16:16 unbound[1248]: [1248:0] error: .: failed lookup, cannot probe to master g.root-servers.net Jun 20 13:16:16 unbound[1248]: [1248:0] error: .: failed lookup, cannot probe to master f.root-servers.net Jun 20 13:16:16 unbound[1248]: [1248:0] error: .: failed lookup, cannot probe to master e.root-servers.net Jun 20 13:16:16 unbound[1248]: [1248:0] error: .: failed lookup, cannot probe to master c.root-servers.net Jun 20 13:16:16 unbound[1248]: [1248:0] error: .: failed lookup, cannot probe to master b.root-servers.net Jun 20 13:16:23 unbound[1248]: [1248:3] info: generate keytag query _ta-4a5c-4f66. NULL IN Jun 20 13:16:24 unbound[1248]: *** buffer overflow detected ***: /usr/sbin/unbound terminated Jun 20 13:16:24 systemd[1]: unbound.service: Main process exited, code=killed, status=6/ABRT Jun 20 13:16:24 systemd[1]: unbound.service: Failed with result 'signal'.
Still reproducible with unbound-1.7.3-1.fc28.x86_64 . I'm not sure why abrt isn't catching this. Arguably this is a serious issue because there's no visual indication to the user why DNS (or, for the layman, network connectivity) isn't working. Maybe adding an auto-restart option to the systemd unit would be a good idea as a work-around for the time being.
Happens to me from time to time with unbound-1.7.3-3.fc28.x86_64
I think this is already reported in bug #1562594. It is hard to distinguish it from the former, but I think this is still the same. Closing as duplicate. *** This bug has been marked as a duplicate of bug 1562594 ***