named hangs up and name resolution is not completed

Issue

Name resolution by named becomes nonresponsive.

Confirmed from the packet capture that it was not responding to the name resolution request from the client.

  14:59:55.275431 IP 192.168.xx.xx.39400 > 192.168.xx.xx.53: 36641+ PTR? xx.xx.168.192.in-addr.arpa. (45)
  15:00:00.692317 IP 192.168.xx.xx.48103 > 192.168.xx.xx.53: 22352+ PTR? xx.xx.168.192.in-addr.arpa. (45)
  15:00:05.692783 IP 192.168.xx.xx.48103 > 192.168.xx.xx.53: 22352+ PTR? xx.xx.168.192.in-addr.arpa. (45)
  15:00:11.112134 IP 192.168.xx.xx.48570 > 192.168.xx.xx.53: 44958+ PTR? xx.xx.168.192.in-addr.arpa. (45)
  15:00:16.117325 IP 192.168.xx.xx.48570 > 192.168.xx.xx.53: 44958+ PTR? xx.xx.168.192.in-addr.arpa. (45)
  15:00:21.512335 IP 192.168.xx.xx.47164 > 192.168.xx.xx.53: 16652+ PTR? xx.xx.168.192.in-addr.arpa. (45)
  15:00:26.517512 IP 192.168.xx.xx.47164 > 192.168.xx.xx.53: 16652+ PTR? xx.xx.168.192.in-addr.arpa. (45)
  15:00:31.873195 IP 192.168.xx.xx.58469 > 192.168.xx.xx.53: 33660+ PTR? xx.xx.168.192.in-addr.arpa. (45)
  15:00:36.874073 IP 192.168.xx.xx.58469 > 192.168.xx.xx.53: 33660+ PTR? xx.xx.168.192.in-addr.arpa. (45)
  15:00:42.294370 IP 192.168.xx.xx.50857 > 192.168.xx.xx.53: 47898+ PTR? xx.xx.168.192.in-addr.arpa. (45)