[READY] Fix recursive lookups against IPv6 interface of core master

[kylerisse]

Description of PR

Found issues with DNS lookups over the IPv6 interface only on the core master server.

Previous Behavior

• serverspec tests for recursive DNS didn't exist
• cache network config for core master had the wrong /64 defined

New Behavior

• serverspec tests for recursive DNS now exist
• cache network config for core master has been corrected

Tests

• serverspec locally
• this PR branch being applied to core master after closing keynote is complete.

[sarcasticadmin]

Partial output for serverspec:

Command "dig @10.0.3.5 +short loghost.scale.lan A | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @10.0.3.5 +short loghost.scale.lan AAAA | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @10.128.3.5 +short loghost.scale.lan A | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @10.128.3.5 +short loghost.scale.lan AAAA | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @2001:470:f026:103::5 +short loghost.scale.lan A | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @2001:470:f026:103::5 +short loghost.scale.lan AAAA | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @2001:470:f026:503::5 +short loghost.scale.lan A | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @2001:470:f026:503::5 +short loghost.scale.lan AAAA | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @10.0.3.5 +short lobste.rs A | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @10.0.3.5 +short lobste.rs AAAA | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @10.128.3.5 +short lobste.rs A | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @10.128.3.5 +short lobste.rs AAAA | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @2001:470:f026:103::5 +short lobste.rs A | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @2001:470:f026:103::5 +short lobste.rs AAAA | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @2001:470:f026:503::5 +short lobste.rs A | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @2001:470:f026:503::5 +short lobste.rs AAAA | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @10.0.3.5 +short google.com A | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @10.0.3.5 +short google.com AAAA | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @10.128.3.5 +short google.com A | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @10.128.3.5 +short google.com AAAA | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @2001:470:f026:103::5 +short google.com A | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @2001:470:f026:103::5 +short google.com AAAA | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @2001:470:f026:503::5 +short google.com A | grep -v -e '^$'"
    exit_status
      is expected to eq 0
  Command "dig @2001:470:f026:503::5 +short google.com AAAA | grep -v -e '^$'"
    exit_status
      is expected to eq 0

[sarcasticadmin]

thanks for helping track this down!