Comment 1 for bug 1865545

This issue can be reproduced by deploying the region and rack controllers in different subnets. The problem comes from the following SQL query @ src/maasserver/routablepairs.py:

_find_addresses_sql = dedent("""\
    SELECT left_node_id, left_ip,
           right_node_id, right_ip
      FROM maasserver_routable_pairs
     WHERE left_node_id IN (%s)
       AND right_node_id IN (%s)
       AND metric < 4
     ORDER BY metric ASC
""")

If the subnets don't share vlan/space, the metric is 4 and the IP is filtered out, rendering a useless chrony conf file for the rack controllers.