Hi Bruce, Kindly Check the actual root cause for this "SERVFAIL" error from the following log messages of your system.
/var/log/messages With Regards. K.Sanjai Gandhi. ----- Original Message ----- From: "Bruce Duncan" <bruce.dun...@ed.ac.uk> To: bind-users@lists.isc.org Sent: Wednesday, January 18, 2023 6:01:32 PM Subject: SERVFAIL IPv6 debugging Hi bind-users, Apologies if this is inappropriate for this list. I am trying to debug a failure to resolve an external name. It appears that when I try to resolve the name ec.europa.eu over IPv6 using either dig +trace or with a caching named that it sometimes fails: [nimbus]root: dig -6 ec.europa.eu ; <<>> DiG 9.11.4-P2-RedHat-9.11.4-26.P2.el7_9.10 <<>> -6 ec.europa.eu ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 29328 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;ec.europa.eu. IN A ;; Query time: 13 msec ;; SERVER: ::1#53(::1) ;; WHEN: Wed Jan 18 12:09:35 GMT 2023 ;; MSG SIZE rcvd: 41 Sometimes I need to rndc flush and try again a few times before it fails. The named log says: 2023-01-18T12:09:35.145500+00:00 nimbus named[11833]: client @0x7f35e6fec700 ::1#35963 (ec.europa.eu): view internet: query failed (SERVFAIL) for ec.europa.eu/IN/A at ../../../bin/named/query.c:8580 Various posts on the web suggest that query.c:8580 is related to dnssec validation, however even with dnssec turned off in /etc/named.conf the query still fails. I've tried setting rndc trace 9 but I get no more information about why the query has failed. Query logging is enabled but there is no information there either. I suspect there is some misconfiguration of the domain. dig -6 +trace sometimes complains that it can't find an address for some servers, but I don't understand why this would make the query fail completely sometimes. Any help appreciated! Thanks, Bruce -- With Regards, K.Sanjai Gandhi. -- Visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information. bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
