;; connection timed out; no servers could be reached

Issue

• DNS resolution fails with error connection timed out.

  # nslookup redhat.com
  ;; connection timed out; no servers could be reached
  

• When performing ping command records in /etc/hosts are used, but with nslookup DNS resolution fails.

  [root@nlams01nwbkp001v discover]# ping localhost
  PING localhost(localhost (::1)) 56 data bytes
  64 bytes from localhost (::1): icmp_seq=1 ttl=64 time=0.038 ms
  64 bytes from localhost (::1): icmp_seq=2 ttl=64 time=0.019 ms
  
  [root@node-0 ~]# nslookup localhost
  ;; connection timed out; no servers could be reached
  
  [root@node-0 ~]# nslookup myhostname.redhat.com
  ;; connection timed out; no servers could be reached