On 2014-05-01 11:20, James B. Byrne wrote:
This morning I see this in the syslog on our primary public DNS host.
internal_send: 142.77.1.1#33950: Connection timed out: 1 Time(s) internal_send: 142.77.1.1#35153: Connection timed out: 1 Time(s) internal_send: 142.77.1.1#35644: Connection timed out: 1 Time(s) internal_send: 142.77.1.1#49394: Connection timed out: 1 Time(s) internal_send: 142.77.1.1#49816: Connection timed out: 1 Time(s) internal_send: 142.77.1.1#49929: Connection timed out: 1 Time(s) internal_send: 142.77.1.1#50281: Connection timed out: 1 Time(s) internal_send: 142.77.1.1#50453: Connection timed out: 1 Time(s) internal_send: 142.77.1.1#50534: Connection timed out: 1 Time(s). . . (x100s)
dig -x 142.77.1.1
; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.23.rc1.el6_5.1 <<>> -x 142.77.1.1 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 31154 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 3
;; QUESTION SECTION: ;1.1.77.142.in-addr.arpa. IN PTR
;; ANSWER SECTION: 1.1.77.142.in-addr.arpa. 604800 IN PTR ns.uunet.ca.
;; AUTHORITY SECTION: 77.142.in-addr.arpa. 86400 IN NS ns.uunet.ca. 77.142.in-addr.arpa. 86400 IN NS AUTH01.NS.UU.NET. 77.142.in-addr.arpa. 86400 IN NS NS2.uunet.ca.
;; ADDITIONAL SECTION: AUTH01.NS.UU.NET. 167 IN A 198.6.1.81 ns.uunet.ca. 86400 IN A 142.77.1.1 NS2.uunet.ca. 86400 IN A 142.77.1.5
;; Query time: 114 msec ;; SERVER: 216.185.71.33#53(216.185.71.33) ;; WHEN: Thu May 1 09:59:50 2014 ;; MSG SIZE rcvd: 176
What is this and why is it happening?
Some of my digging turns up the possibility that your system is trying to perform IPv6 DNS queries against an IPv4 DNS server.