'Cannot determine the IP address of the site' during installation

**DRAFT**

Error messages during install:

    IP configuration
  --------------------

    Test Status: FAILED
    Program Output:
      Cannot determine the IP address of the site
      See the Vertica Troubleshooting Guide for more information.

    IP and Netmask consistency
  ------------------------------
    Sites x4150-13 and x4150-14 have different subnet masks [] and ['255.255.248.0']

    Test Status: FAILED
    Program Output:
      Sites x4150-13 and x4150-14 have different subnet masks [] and ['255.255.248.0']
      See the Vertica Troubleshooting Guide for more information.


Problem could be that the hostname is listed twice in /etc/hosts.  We ignore the ipv6 ::1 line, but in this case x4150-13 is listed both for 127.0.0.1 and 10.58.17.202.


127.0.0.1               x4150-13 localhost.localdomain localhost
::1             x4150-13 localhost6.localdomain6 localhost6
10.58.17.202     x4150-13       vertica1.stage