What is the maximum number of dynamic VIPAs (DVIPAs) allowed on a single TCPIP stack?

Prior to z/OS Communications Server V2R2, the upper limit on the total number of DVIPAs on a single TCP/IP stack was 1024. This limit included:

• All DVIPAs defined with VIPADEFINE

• All DVIPAs defined with VIPABACKUP

• All deactivated DVIPAs

• All application instance DVIPAs (defined with VIPARANGE)

Starting with z/OS Communications Server V2R2, the upper limit of 1024 DVIPAs is increased to 4096. DVIPAs defined with VIPADEFINE and VIPABACKUP and target of a VIPADISTRIBUTE are still limited to 1024. The previous limit of 1024 IPv4 VIPARANGE statements and 1024 IPv6 VIPARANGE statements is also increased in V2R2 to 4096 for each type of VIPARANGE statement.

Run netstat VIPADYN/-v to list all dynamic virtual IP addresses on the stack.

If the number of DVIPAs you attempted to define on a single TCPIP stack exceeds the upper limit, the following error message is issued:

 EZZ8309I TOO MANY VIPAS - ip_addr REJECTED

where ip_addr is the IP address of the dynamic VIPA that put the stack over the maximum allowed.

Perform the following procedure for problem resolution with message EZZ8309I:

1. As stated in EZZ8309I message explanation, the system programmer response is to reduce the number of defined or backup DVIPAs for this stack. [Note: The text in the explanation mentions these potential statements that might need reduction in number of DVIPAs: VIPADEFINE, VIPABACKUP, and VIPARANGE.]

2. Set SLIP on message EZZ8309I to capture dumps of TCPIP and VTAM address spaces to view the TCPIPCS XCF report for the DVIPA statistical counters and to identify the offender based on the exception records in the SYSTCPIP CTRACE. Note that the exception records are always written to the internal buffers in the TCPIP address space. Once the offender has been identified, take appropriate action to ensure that it does not consume too many DVIPA resources.