Duplicate IP addresses
The OSA-Express adapter recognizes duplicate IP addresses on the same OSA-Express adapter or in the network using ARP and prevents duplicates.
About this task
Several setups require duplicate addresses:
- To perform IP takeover you need to be able to set the IP address to be taken over. This address exists prior to the takeover. See Taking over IP addresses for details.
- For proxy ARP you need to register an IP address for ARP that belongs to another Linux® instance. See Configuring a device for proxy ARP for details.
- For VIPA you need to assign the same virtual IP address to multiple devices. See Configuring a device for virtual IP address (VIPA) for details.
You can use the qethconf command (see qethconf - Configure qeth devices) to maintain a list of IP addresses that your device can take over, a list of IP addresses for which your device can handle ARP, and a list of IP addresses that can be used as virtual IP addresses, regardless of any duplicates on the same OSA-Express adapter or in the LAN.