Configure Network Names

Configure each host in the cluster as follows to ensure that all members can communicate with each other:

1. Set the hostname to a unique name (not localhost).

   sudo hostnamectl set-hostname foo-1.example.com

2. Edit /etc/hosts with the IP address and fully qualified domain name (FQDN) of each host in the cluster. You can add the unqualified name as well.

   1.1.1.1  foo-1.example.com  foo-1
   2.2.2.2  foo-2.example.com  foo-2
   3.3.3.3  foo-3.example.com  foo-3
   4.4.4.4  foo-4.example.com  foo-4

3. Edit /etc/sysconfig/network with the FQDN of this host only:

   HOSTNAME=foo-1.example.com

4. Verify that each host consistently identifies to the network:
   1. Run uname -a and check that the hostname matches the output of the hostname command.
   2. Run /sbin/ifconfig and note the value of inet addr in the eth0 (or bond0) entry, for example:

      eth0      Link encap:Ethernet  HWaddr 00:0C:29:A4:E8:97  
                inet addr:172.29.82.176  Bcast:172.29.87.255  Mask:255.255.248.0
      ...

   3. Run host -v -t A $(hostname) and verify that the output matches the hostname command.

      The IP address should be the same as reported by ifconfig for eth0 (or bond0):

      Trying "foo-1.example.com"
      ...
      ;; ANSWER SECTION:
      foo-1.example.com. 60 IN
      A
      172.29.82.176