How to Configure an Active-Standby IPMP Group

The following procedure describes how to configure an IPMP group in which one interface is kept as a standby interface. This interface is deployed only when an active interface in the group fails.

For overview information about standby interfaces, see Types of IPMP Interface Configurations.

1. Become the root role.
2. Create an IPMP interface.

   # ipadm create-ipmp ipmp-interface

   where ipmp-interface specifies the name of the IPMP interface.

3. Add the underlying IP interfaces to the group.

   # ipadm add-ipmp -i under-interface1 [-i underinterface2 ...] ipmp-interface

   where under-interface refers to the underlying interface of the IPMP group. You can add as many IP interfaces as are available on the system.

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   Note -  In a dual-stack environment, placing the IPv4 instance of an interface under a particular IPMP group automatically places the IPv6 instance under the same group.

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4. Add the data addresses to the IPMP interface.

   # ipadm create-addr -a address ipmp-interface

   where address can be in CIDR notation.

5. If you use probe-based failure detection with test addresses, add the test addresses on the underlying interfaces.

   # ipadm create-addr -a address under-interface

   where address can be in CIDR notation. All test IP addresses in an IPMP group must belong to a single IP subnet and therefore using same network prefix.

6. Configure one of the underlying interfaces as a standby interface.

   # ipadm set-ifprop -p standby=on -m ip under-interface

The following example shows how to create an active-standby IPMP configuration.

First, the IPMP interface is created.

# ipadm create-ipmp ipmp0

The underlying IP interfaces are then created and added to the IPMP interface.

# ipadm create-ip net0
# ipadm create-ip net1
# ipadm create-ip net2

# ipadm add-ipmp -i net0 -i net1 -i net2 ipmp0

Next, IP addresses are assigned to the IPMP interface. IP addresses that are assigned to the IPMP interface are data addresses. In this example, the IPMP interface has two data addresses.

# ipadm create-addr -a 192.168.10.10/24 ipmp0
ipadm: ipmp0/v4
# ipadm create-addr -a 192.168.10.15/24 ipmp0
ipadm: ipmp0/v4a

The IP address in this example includes the prefixlen property, which is expressed as a decimal number. The prefixlen portion of the IP address specifies the number of left-most contiguous bits of the address that comprise the IPv4 netmask or the IPv6 prefix of the address. The remaining low-order bits define the host part of the address. When the prefixlen property is converted to a text representation of the address, the address contains 1's for the bit positions that are to be used for the network part and 0's for the host part. This property is not supported on the dhcp address object type. For more information, see the ipadm (1M) man page.

IP addresses are then assigned to the underlying IP interfaces of the IPMP group. IP addresses that are assigned to the underlying interfaces are test addresses to be used for probe-based failure detection.

# ipadm create-addr -a 192.168.10.30/24 net0
ipadm: net0/v4
# ipadm create-addr -a 192.168.10.32/24 net1
ipadm: net1/v4
# ipadm create-addr -a 192.168.10.34/24 net2
ipadm: net2/v4

Lastly, the net2 interface is configured as a standby interface.

# ipadm set-ifprop -p standby=on net2

The administrator can view the IPMP configuration by using the ipmpstat command.

# ipmpstat -g
GROUP     GROUPNAME   STATE      FDT        INTERFACES
ipmp0     ipmp0      ok         10.00s     net0 net1 (net2)

# ipmpstat -t
INTERFACE  MODE     TESTADDR        TARGETS
net0       routes   192.168.10.30   192.168.10.1
net1       routes   192.168.10.32   192.168.10.1
net2       routes   192.168.10.34   192.168.10.5