Recent releases of Ceph can work with either IPv4 or IPv6 addressing, but not both simultaneously. It is very common for the Ceph private aka replication network to be provisioned with non-routable IPs for example, RFC-1918 to conserve address space or increase privacy. While IPv6 is inarguably the best path into the future given the exhaustion of IPv4, many organizations have been slow to migrate. It is common to exploit the expansive 10.0.0.0 RFC-1918 network internally for systems that do not need to be reached from the Internet at large. This is one way that organizations have put off the difficult transition to IPv6. The choice for your deployment will likely be out of your hands, but it should be considered.

In Chapter 3, Hardware and Network Selection, we discussed networking strategies for Ceph clusters. When devising a bonding strategy you will need to work with your network team, but we'll offer some guidance. With any networking topology it is highly advised...