VIPADYNAMIC - VIPABACKUP statement

Designates one or more dynamic VIPAs (DVIPAs) for which this stack provides automatic backup if the owning stack fails. Another stack is expected, but not required, to have this same DVIPA defined with a VIPADYNAMIC VIPADEFINE statement.

Rule:

Within a single profile there should be only one VIPABACKUP statement for a particular DVIPA. If the DVIPA does appear in more than one statement, you must specify a VIPADELETE statement before the last instance to ensure that it is not rejected.

Syntax

Rule:

Specify the parameters in the order shown here.


                                                    .-----------.                                                            
               .-1----.                             V           |                                                            
>>-VIPABackup--+------+--+---------------------+--+---ipv4_addr-+--------------------------------------------------------+-><
               '-rank-'  +-TIER1---------------+  +-ipv6_intfname--ipv6_addr---------------------------------------------+   
                         +-TIER2--+----------+-+  |                                                        .-----------. |   
                         |        '-CPCSCOPE-' |  |                                                        V           | |   
                         '-CPCSCOPE------------'  +-MOVEable--+-IMMEDiate-+--+------------+--address_mask----ipv4_addr-+-+   
                                                  |           '-WHENIDLE--'  '-SERVICEMGR-'                              |   
                                                  '-MOVEable--IMMEDiate--ipv6_intfname--+-ipv6_addr------------+---------'   
                                                                                        '-ipv6_addr/prefix_len-'

Parameters

rank

Specifies the intended order of the VIPAs in this VIPABACKUP statement list in their respective backup chains, relative to other stacks in those backup chains. Larger numerical rank values move the respective stacks closer to the beginning of the backup chain.

rank can be set to any integer from 1 (end of the backup chain) through 254 (start of the backup chain). Values 0 and 255 are reserved for use by the stacks themselves to temporarily force stack entries to the start or the end of the backup chain until an expected transition takes place.

The default is a rank of 1.

TIER1

Indicates that the dynamic VIPA whose address is specified as an IP address on this statement are used to distribute incoming requests to z/OS® or non-z/OS targets (for example, DataPower® appliances).

Restriction: You cannot configure this parameter on this statement if CPCSCOPE is configured.

TIER2

Indicates that the dynamic VIPA whose address is specified as an IP address on this statement are used to distribute incoming requests from Tier 1 targets to the group of server applications.

Rule: If CPCSCOPE is also configured on this statement, then the Tier 2 group of server applications is limited to TCP/IP stacks on this CPC.

CPCSCOPE

Indicates that the dynamic VIPA whose address is specified as an IP address on this statement is specific to the central processor complex (CPC) on which it is defined. The VIPA is not moved to or taken over by another TCP/IP stack that is in a different CPC. A DVIPA defined with this characteristic can be used as the default route for incoming requests from Tier 1 targets on this CPC. A DVIPA defined with this characteristic can be used as the default route for incoming requests from non-z/OS tier 1 targets on this CPC. The non-z/OS Tier 1 target addresses must be on the same subnet as the subnet determined by the address_mask or prefix_len value.

Restrictions:

A DVIPA defined with the CPCSCOPE parameter cannot be used in a VIPADISTRIBUTE DEFINE statement unless TIER2 is also configured.
You cannot configure this parameter on this statement if TIER1 is configured.

MOVEABLE

This parameter is used to specify when a DVIPA that has been activated on this TCP/IP stack can be moved to another TCP/IP stack when the other TCP/IP stack requests ownership.

It can also be used to specify that the dynamic VIPA should be activated on this TCP/IP stack if it is not already active in the sysplex. If the DVIPA is already active in the sysplex when the VIPABACKUP statement is processed, this parameter is ignored. If you specify this parameter, you must also specify one of the following sets of dynamic VIPA information:

The IPv4 address mask and address
The IPv6 interface name and address

For more information about configuring VIPAs for activation with VIPABACKUP, see z/OS Communications Server: IP Configuration Guide.

IMMEDIATE

Specifies that the DVIPA can be activated immediately on another TCP/IP stack. The TCP connections to this TCP/IP stack are preserved. If the DVIPA has been activated on this TCP/IP, and the TCP/IP where the DVIPA is defined by a VIPADEFINE statement is subsequently activated, the DVIPA is activated immediately on that TCP/IP. And the TCP connections to this TCP/IP are preserved.

WHENIDLE

Specifies that the DVIPA remains active on this TCP/IP stack until there are no more connections to the DVIPA on this stack. If the DVIPA is activated on this TCP/IP, and the TCP/IP where the DVIPA is defined by a VIPADEFINE statement is subsequently activated, the DVIPA remains active on this TCP/IP until there are no more connections to the DVIPA on this TCP/IP.

This option is not supported for IPv6.

Guideline: Support for the WHENIDLE parameter is limited. It is recommended to use the IMMEDIATE parameter instead of the WHENIDLE parameter

SERVICEMGR

Indicates that sysplex distributor performs Multinode Load Balancing (MNLB) by functioning as a Service Manager (in place of Cisco's LocalDirector) for these distributed dynamic VIPAs. SERVICEMGR has no effect if a VIPADISTRIBUTE DEFINE statement does not exist for the dynamic VIPA or VIPAs. SERVICEMGR is optional, and can be specified on a VIPABACKUP statement only when MOVEABLE is also specified.

This parameter is used only for activating the DVIPA when it is not already active in the sysplex. If the DVIPA is active when the VIPABACKUP statement is processed, this parameter is ignored.

Restrictions:

MNLB is not supported for IPv6 DVIPAs; the SERVICEMGR parameter is ignored for these types of addresses.
The SERVICEMGR parameter is ignored when TIER1, TIER2, or CPCSCOPE is specified.

address_mask

Specifies the subnet mask or prefix to be used when building the BSDROUTINGPARMS entry for this DVIPA when it is activated. This parameter can be specified on a VIPABACKUP statement only when MOVEABLE is also specified, and this parameter is required when MOVEABLE is specified on a VIPABACKUP statement. It is specified in standard dotted decimal notation. A subnet mask of 0.0.0.0 is not valid.

When you are specifying the subnet mask for a DVIPA with the value CPSCOPE, ensure that the subnet is the same subnet that is used for tier 1 non-z/OS targets that are being routed to tier 2 targets on this CPC.

This parameter is used only for activating the DVIPA when it is not already active in the sysplex. If the DVIPA is active when the VIPABACKUP statement is processed, this parameter is ignored.

Restriction: This parameter applies to IPv4 only.

ipv4_addr

Specifies the specific DVIPA to be backed up. More than one IPv4 address can be specified on a single VIPABACKUP statement. A mixture of IPv4 addresses and an IPv6 interface on the same VIPABACKUP statement is not permitted. A mixture of a VIPABACKUP statement with all IPv4 addresses, and a VIPABACKUP statement with an IPv6 interface, is permitted within the same VIPADYNAMIC/ENDVIPADYNAMIC block, and the VIPABACKUP statements can be intermixed in any order.

All ipv4_addr values specified on a single VIPABACKUP statement have the same rank. Use multiple VIPABACKUP statements to define different ranks for different ipv4_addr values.

The default LOOPBACK address (127.0.0.1) cannot be specified as the ipv4_addr.

ipv6_addr

Specifies the specific DVIPA to be backed up. Only one IPv6 address can be specified on a single VIPABACKUP statement. A mixture of VIPABACKUP statements with all IPv4 addresses, and VIPABACKUP statements with the IPv6 address, is permitted within the same VIPADYNAMIC/ENDVIPADYNAMIC block, and the VIPABACKUP statements can be intermixed in any order.

See Restrictions on IPv6 addresses configured in the TCP/IP profile for a description of the ipaddr_spec parameter and a list of restrictions that must be observed when specifying this parameter.

/prefix_len

Specifies the prefix length to be used when calculating a prefix for CPCSCOPE processing. The number of bits in the ipv6_addr value defines the prefix. The range is 1 - 128.

When specifying the prefix length for a CPCSCOPE DVIPA, ensure that the prefix is the same subnet used for the tier 1 targets that are in this CPC.

Restriction: This parameter applies to IPv6 only.

ipv6_intfname

The name of the IPv6 interface to be backed up. The maximum length is 16 characters. Only one ipv6_intfname can be specified on a single VIPABACKUP statement. This specified name and the address specified in ipv6_addr are verified to ensure that the DVIPA interface is uniquely (consistently) defined throughout the sysplex environment.

Steps for modifying

To remove an IPv4 address or IPv6 interface as a dynamic VIPA backup, use one of the following:
- For an IPv4 address: VIPADELETE ipv4_addr
- For an IPv6 interface: VIPADELETE ipv6_intfname
- To change the rank (if the IP address is not currently active on this stack):
```
VIPABACKUP  new_rank ipv4_addr
```
  However, if the IP address is currently active, you must first delete it and then configure it with the new rank by using one of the following:
  - ```
  VIPADELETE   ipv4_addr 
  VIPABACKUP  new_rank  ipv4_addr
```
- ```
VIPABACKUP new_rank ipv6_intfname ipv6_addr
```
  or if the IP address is currently active, the VIPADELETE statement breaks any existing connections and causes the dynamic VIPA to activate elsewhere in the sysplex if there is another stack prepared to activate it.
To remove an IPv6 interface and its address as a dynamic VIPA backup, use a VIPADELETE statement. ipv6_intfname.
To modify the VIPABACKUP or VIPADELETE ipv6_intfname statement to remove an IP address as a dynamic VIPA backup, code the following:
```
VIPADELETE ipaddr
```
To change a VIPABACKUP from TIER1 to TIER2, from TIER2 to TIER1, from non-TIER to TIER, or from TIER to non-TIER, you must first issue a VIPADELETE ipaddr.

Examples

VIPABACKUP  V6DVIPA1 2000::9:67:240:2
VIPABACKUP  200 TIER2 CPCSCOPE MOVEABLE IMMEDIATE 255.255.255.192 9.67.240.02