Prerequisites for cluster peering

Connectivity requirements

The subnet used in each cluster for intercluster communication must meet the following requirements:

• The subnet must belong to the broadcast domain that contains the ports that are used for intercluster communication.
• The IP addresses that are used for intercluster LIFs do not need to be in the same subnet, but having them in the same subnet is a simpler configuration.
• You must have decided whether the subnet is dedicated to intercluster communication or is shared with data communication.

Each node must have an intercluster LIF with an IP address on the intercluster network.

The intercluster network must be configured so that cluster peers have pair-wise full-mesh connectivity within the applicable IPspace, which means that each pair of clusters in a cluster peer relationship has connectivity among all of their intercluster LIFs.

A cluster’s intercluster LIFs have an IPv4 address or an IPv6 address.

Port requirements

The ports that are used for intercluster communication must meet the following requirements:

• All ports that are used to communicate with a given remote cluster must be in the same IPspace.

  You can use multiple IPspaces to peer with multiple clusters. Pair-wise full-mesh connectivity is required only within an IPspace.

• The broadcast domain that is used for intercluster communication must include at least two ports per node so that intercluster communication can fail over from one port to another port.

  Ports added to a broadcast domain can be physical network ports, VLANs, or interface groups (ifgrps).

• All ports must be cabled.
• All ports must be in a healthy state.
• The MTU settings of the ports must be consistent.
• You must decide whether the ports that are used for intercluster communication are shared with data communication.

Firewall requirements

Firewalls and the intercluster firewall policy must allow the following protocols:

• ICMP service
• TCP to the IP addresses of all the intercluster LIFs over the ports 10000, 11104, and 11105
• HTTPS

The default intercluster firewall policy allows access through the HTTPS protocol and from all IP addresses (0.0.0.0/0), but the policy can be altered or replaced.

Cluster requirements

Clusters must meet the following requirements:

• The time on the clusters in a cluster peering relationship must be synchronized within 300 seconds (5 minutes).

  Cluster peers can be in different time zones.