Enable Ceph multinetwork#

Ceph allows establishing multiple IP networks and subnet masks for clusters with configured L3 network rules. You can configure multi-network through the network section of the CephDeployment custom resource (CR). Pelagia Deployment Controller uses this section to specify the Ceph networks for external access and internal daemon communication. The parameters in the network section use the CIDR notation, for example, 10.0.0.0/24.

Before enabling multiple networks for a Ceph cluster, consider the following requirements:

Do not confuse the IP addresses you define with the public-facing IP addresses the network clients may use to access the services.
If you define more than one IP address and subnet mask for the public or cluster network, ensure that the subnets within the network can route to each other.
Include each IP address or subnet in the network section to IP tables and open ports for them as necessary.
The pods of the Ceph OSD and Ceph RADOS Gateway daemons use cross-pods health checkers to verify that the entire Ceph cluster is healthy. Therefore, each CIDR must be accessible inside Ceph pods.
Avoid using the 0.0.0.0/0 CIDR in the network section. With a zero range in publicNet and/or clusterNet, the Ceph daemons behavior is unpredictable.

Enable multinetwork for Ceph#

Open CephDeployment CR for editing:
```
kubectl -n pelagia get cephpdl
```
In the clusterNet and/or publicNet parameters of the network section, define a comma-separated array of CIDRs. For example:
```
spec:
  network:
    publicNet:  10.12.0.0/24,10.13.0.0/24
    clusterNet: 10.10.0.0/24,10.11.0.0/24
```
Exit the editor and apply the changes.

Once done, the specified network CIDRs will be passed to the Ceph daemons pods through the Rook rook-config-override ConfigMap.