During ceph-deploy for 1.3.1 installation after running "ceph-deploy new <initial-monitor-node(s)>" ceph.conf will have IPv6 address of mon nodes even though IPv4 is available , not sure whether this is problem with ceph-deploy or DNS resolution hence logging the bug. In earlier versions it was picking only IPv4. Version :- ceph-deploy-1.5.25-3.el7cp.noarch