Networks in a cluster domain

To configure elements of your cluster domain that are related to networks, you can use Db2® high availability instance configuration utility (db2haicu) to add a physical network to your cluster domain. A physical network is composed of: network interface cards, IP addresses, and subnetwork masks.

Network interface cards

A network interface card (NIC) is hardware that connects a computer (also called a cluster node) to a network. A NIC is sometimes referred to as an interface, a network adaptor, or an adaptor. When you use db2haicu to add a physical network to your cluster domain, you specify at least one NIC including: the host name of the computer to which the NIC belongs; the name of the NIC on that host computer; and the IP address of the NIC.

IP addresses

An Internet Protocol address (IP address) is a unique address on a network. In IP version 4, an IP address is 32 bits large, and is normally expressed in dot-decimal notation like this: 129.30.180.16. An IP address is composed of a network portion and a host computer portion.

Subnetwork masks

A network can be partitioned into multiple logical subnetworks using subnetwork masks. A subnetwork mask is a mechanism for moving some bits of the host portion of an IP address to the network portion of the IP address. When you use db2haicu to add an IP address to your cluster domain, you will sometimes need to specify the subnetwork mask for the IP address. For example, when you use db2haicu to add a NIC, you must specify the subnetwork mask for the IP address of the NIC.

Network equivalencies

An equivalency is a set of resources that provide the same functionality as each other and can fail over for each other. When you create a network using db2haicu, the NICs in that network can fail over for each other. Such a network is also referred to an a network equivalency.

Network protocols

When you use db2haicu to add a network to your cluster domain, you must specify the type of network protocol being used. Currently, only the TCP/IP network protocol is supported.

Usage note

Configuring a network resource via db2haicu is only required if configuring a virtual IP (VIP) address or if there are Db2 resources whose availability is dependent on the availability of the network in question. Network adapters that are in different subnets (or equivalently, in different virtual local area networks) cannot be added to the same network. A VIP address cannot failover between different subnets or virtual local area networks.