I have noticed that I get occasional (fast) SERVFAIL responses from "dig NS iq.", e.g.
$ dig ns iq. ; <<>> DiG 9.9.4 <<>> ns iq. ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 7919 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;iq. IN NS ;; Query time: 413 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Tue Sep 24 15:06:55 BST 2013 ;; MSG SIZE rcvd: 31 but that trying again immediately gives the right result: $ dig ns iq. ; <<>> DiG 9.9.4 <<>> ns iq. ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 60361 ;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 7 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;iq. IN NS ;; ANSWER SECTION: iq. 86400 IN NS nsp-anycast.cmc.iq. iq. 86400 IN NS sns-pb.isc.org. iq. 86400 IN NS ns1.cmc.iq. iq. 86400 IN NS iq.dns.cocca.org.nz. ;; ADDITIONAL SECTION: iq.dns.cocca.org.nz. 172798 IN A 203.119.84.235 ns1.cmc.iq. 172798 IN A 194.117.57.100 sns-pb.isc.org. 74136 IN A 192.5.4.1 sns-pb.isc.org. 74136 IN AAAA 2001:500:2e::1 nsp-anycast.cmc.iq. 172798 IN A 194.117.58.42 nsp-anycast.cmc.iq. 172798 IN AAAA 2001:500:14:8001:ad::42 ;; Query time: 33 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Tue Sep 24 15:06:57 BST 2013 ;; MSG SIZE rcvd: 260 The nameserver at 127.0.0.1 is running BIND 9.9.4 (the same effect was observed with beta and rc versions earlier, and I can provoke it with 9.9.3-P2 on another server as well). "iq" is partially signed, in the sense that some of its nameservers deliver a signed version, and some an unsigned one, but I don't see how that leads to the effect observed. -- Chris Thompson Email: c...@cam.ac.uk _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
