Stage 3: Issuing a command to take over the address

Red Hat Enterprise Linux 8.6 LPAR mode z/VM guest

To complete taking over a specific IP address and remove it from the CHPID or LPAR that previously held it, issue an ip addr or equivalent command.

Before you begin

Both the device that is to take over the IP address and the device that is to surrender the IP address must be enabled for IP takeover. This rule applies to the devices on both OSA-Express and HiperSockets CHPIDs. (See Stage 1: Enabling a qeth group device for IP takeover).
The IP address to be taken over must have been activated for IP takeover (see Stage 2: Activating and deactivating IP addresses for takeover).

About this task

Be aware of the information in Confirming that an IP address has been set under layer 3 when using IP takeover.

Examples

IPv4 example:

To make a HiperSockets device enca1c0 take over IP address 192.168.10.22 issue:

# ip addr add 192.168.10.22/24 dev enca1c0

For IPv4, the IP address you are taking over must be different from the one that is already set for your device. If your device already has the IP address it is to take over, you must issue two commands: First remove the address to be taken over if it is already there. Then add the IP address to be taken over.

For example, to make a HiperSockets device enca1c0 take over IP address 192.168.10.22 if enca1c0 is already configured to have IP address 192.168.10.22 issue:

# ip addr del 192.168.10.22/24 dev enca1c0
# ip addr add 192.168.10.22/24 dev enca1c0

IPv6 example:

To make a device encd300 take over fec0::111:25ff:febd:d9da/64 issue:

ip addr add fec0::111:25ff:febd:d9da/64 nodad dev encd300

For IPv6, setting the nodad (no duplicate address detection) option ensures that the encd300 interface uses the IP address fec0::111:25ff:febd:d9da/64. Without the nodad option, the previous owner of the IP address might prevent the takeover by responding to a duplicate address detection test.

The IP address you are taking over must be different from the one that is already set for your device. If your device already has the IP address it is to take over you must issue two commands: First remove the address to be taken over if it is already there. Then add the IP address to be taken over.

For example, to make a device encd300 take over IP address fec0::111:25ff:febd:d9da/64 when encd300 is already configured to have that particular IP address issue:

ip addr del fec0::111:25ff:febd:d9da/64 nodad dev encd300
ip addr add fec0::111:25ff:febd:d9da/64 nodad dev encd300