Public Networks

Public networks communicate outside the cluster. Consider the following points when you plan your public-network configuration:

• Separation of public and private network – Public networks and the private network (cluster interconnect) must use separate adapters, or you must configure tagged VLAN on tagged-VLAN capable adapters and VLAN-capable switches to use the same adapter for both the private interconnect and the public network.

• Minimum – All cluster nodes must be connected to at least one public network. Public-network connections can use different subnets for different nodes.

• Maximum – You can have as many additional public-network connections as your hardware configuration allows.

• Scalable services – All nodes that run a scalable service must either use the same subnet or set of subnets or use different subnets that are routable among themselves.

• IPv4 – Sun Cluster software supports IPv4 addresses on the public network.

• IPv6 – Sun Cluster software supports IPv6 addresses on the public network under the following conditions or restrictions:

  • Sun Cluster software does not support IPv6 addresses on the public network if the private interconnect uses SCI adapters.

  • Sun Cluster software supports IPv6 addresses for both failover and scalable data services.

• IPMP groups – Each public-network adapter that is used for data-service traffic must belong to an IP network multipathing (IPMP) group. If a public-network adapter is not used for data-service traffic, you do not have to configure it in an IPMP group.

  In the Sun Cluster 3.2 11/09 release, the scinstall utility no longer automatically configures a single-adapter IPMP group on each unconfigured public-network adapter during Sun Cluster creation. Instead, the scinstall utility automatically configures a multiple-adapter IPMP group for each set of public-network adapters in the cluster that uses the same subnet. On the Solaris 10 OS, these groups are probe based.

  The scinstall utility ignores adapters that are already configured in an IPMP group. You can use probe-based IPMP groups or link-based IPMP groups in a cluster. But probe-based IPMP groups, which test the target IP address, provide the most protection by recognizing more conditions that might compromise availability.

  If any adapter in an IPMP group that the scinstall utility configures will not be used for data-service traffic, you can remove that adapter from the group.

  For guidelines and instructions to configure IPMP groups, follow the procedures in Part VI, IPMP, in System Administration Guide: IP Services. To modify IPMP groups after cluster installation, follow the guidelines in How to Administer IP Network Multipathing Groups in a Cluster in Sun Cluster System Administration Guide for Solaris OS and procedures in Chapter 28, Administering Network Multipathing (Task), in System Administration Guide: IP Services (Solaris 9) or Chapter 31, Administering IPMP (Tasks), in System Administration Guide: IP Services(Solaris 10).

• Local MAC address support – All public-network adapters must use network interface cards (NICs) that support local MAC address assignment. Local MAC address assignment is a requirement of IPMP.

• local-mac-address setting – The local-mac-address? variable must use the default value true for Ethernet adapters. Sun Cluster software does not support a local-mac-address? value of false for Ethernet adapters. This requirement is a change from Sun Cluster 3.0, which did require a local-mac-address? value of false.

For more information about public-network interfaces, see Sun Cluster Concepts Guide for Solaris OS.