IBM Support

Manually adding/removing interface alias/secondary addresses

Question/Answer


Question

Can TSAMP be stopped while still keep the underlying managed resources online, including the virtual IP address. If so, how could the virtual IP address be manually moved from node to node while TSAMP is disabled?

Answer

TSAMP can be stopped while keeping the resources online. Simply stop the domain using the -f (force) option with the stoprpdomain command.

To manually add an alias/secondary address (virtual IP address) to a network interface, use the following syntax of the ifconfig command:

For AIX:
ifconfig <interface_name> inet <virtual_ip_address> netmask <netmask> alias
For example:
ifconfig en0 inet 10.10.10.219 netmask 255.255.255.0 alias

For Linux:
ifconfig <secondary_interface_name> <virtual_ip_address> netmask <netmask>
For example:
ifconfig eth0:0 10.10.20.218 netmask 255.255.255.0


To manually remove an alias or secondary address, use the following syntax:

For AIX:
ifconfig <interface_name> inet <virtual_ip_address> delete
For example:
ifconfig en0 inet 10.10.10.219 delete

For Linux:
ifconfig <secondary_interface_name> del <virtual_ip_address>
For example:
ifconfig eth0:0 del 10.10.20.218


To check whether an interface has an alias/secondary IP address assigned or not (on the current node), use the following syntax:
ifconfig -a

For AIX, the alias IP address will be shown under the existing interface name, usually listed directly underneath the real IP address for the interface. For Linux, a new interface name with the syntax "<if_name>:<number>", for example "eth0:0" will be shown, and it will contain the virtual IP address.

A couple of comments:
1) All the above commands are specific to the node they are run on. They are NOT cluster wide in scope.
2) To manually move a virtual IP address from node to node, it actually involves manually removing the alias IP address on one node, and then manually creating an alias IP address on another node using the same virtual IP address.
3) The above ifconfig commands for assigning and deleting alias can be used any time a virtual IP address needs to be manually created, however TSAMP would either need to be in manual mode, or completely shutdown (when node/domain taken offline using stoprp... commands) if there was a corresponding ServiceIP defined with the same IP address. This is because TSAMP will attempt to maintain either an online or offline status for its ServiceIP resource, thus would potential counter your manual actions, such as deleting an alias you just created if its ServiceIP resource was defined with the same IP address and was set to be offline.
4) You would not need to remove the alias/secondary address entry in order to be able to re-introduce TSAMP.

Document information

More support for: Tivoli System Automation for Multiplatforms

Component: --

Software version: 3.1, 3.2, 3.2.1, 3.2.2, 4.1

Operating system(s): AIX, Linux

Reference #: 1294045

Modified date: 13 February 2019