Verifying the node hostname and time settings

Ensure that the node hostname and IP address is resolvable by DNS and node time is set to a well-known NTP.

For Kerberos the hostname is used for the Service Principal name, therefore the hostname must resolve to the correct IP address. (See Principal names and DNS. Kerberos authentication is sensitive to system time, manually set system clocks may cause issues. Ensure that node time is set to a well-known NTP.

Procedure

  1. To verify the hostname: 
    nslookup $(hostname --fqdn) && hostname --fqdn && hostname -i
    Server:		10.200.1.10
Address:	10.200.1.10#53

Name:	node.example.com
Address: 10.200.182.183

node.example.com
10.200.182.183
  2. On each node, confirm that NTP is configured and running: 
    ntpq -p
    
remote           refid            st t when poll reach   delay   offset  jitter
==============================================================================
*li506-17.member 209.51.161.238   2  u 331 1024  377   80.289    1.384   1.842
-tock.eoni.com   216.228.192.69   2  u 410 1024  377   53.812    1.706  34.692
+time01.muskegon 64.113.32.5      2  u 402 1024  377   59.378   -1.635   1.840
-time-a.nist.gov .ACTS.           1  u 746 1024  151  132.832   26.931  55.018
+golem.canonical 131.188.3.220    2  u 994 1024  377  144.080   -1.732  20.072