Steps for increasing the MAXSOCKETS value

The following steps assume that you want to make a permanent change to the MAXSOCKETS value without having to stop and then restart z/OS® UNIX.

Restriction: This procedure can only be used if you have specified DOMAINNAME(AF_INET) or DOMAINNAME(AF_INET6). MAXSOCKETS is always set to 10000 for AF_UNIX and any MAXSOCKETS value specified on the NETWORK statement is ignored.

Before you begin: You need to know what MAXSOCKETS value you want to use, and you must have specified either DOMAINNAME(AF_INET) or DOMAINNAME(AF_INET6).

Perform the following steps to increase the MAXSOCKETS value.

Create a temporary parmlib member, BPXPRMtt, and add the following information:
```
NETWORK TYPE(INET) MAXSOCKETS(200000)
   DOMAINNAME(AF_INET)  DOMAINNUMBER(2) 
```
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Activate the updated BPXPRMtt member.
```
SETOMVS RESET=(tt)
```
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To make the change permanent, update the MAXSOCKETS value in the BPXPRMxx member that is used on IPL.
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When you are done, you have increased the MAXSOCKETS value.

Tip: You can add support for AF_INET6 to a running system for the first time. To do so, the NETWORK statement would specify DOMMAINNAME(AF_INET6) and DOMAINNUMBER(19). TCPIP would have to be recycled for this to take effect. You can add AF_INET6 in this way to an INET or as discussed in the next step to a CINET configuration. You can also change the MAXSOCKETS value for a CINET configuration with a similar procedure:

The TYPE() keyword of the NETWORK statement would specify the TYPE name of the CINET INET PFS, which was "CINET" in the previous examples.
INADDRANYPORT cannot be changed.
INADDRANYCOUNT can be increased for DOMAINNAME(AF_INET). INADDRANYCOUNT for AF_INET6 is ignored. The reserved port range for CINET is shared across both address families and the values are taken from the AF_INET statement. The maximum value allowed for INADDRANYCOUNT is 8000.
If you only want to increase MAXSOCKETS, and if INADDRANYCOUNT and INADDRANYPORT were specified on the NETWORK statement used during initialization, specify INADDRANYCOUNT and INADDRANYPORT the same way for the SET OMVS. If you omit them from the NETWORK statement, the default value of INADDRANYCOUNT=1000 is used.
Before INADDRANYCOUNT is increased, the PORTRANGE statement in the TCP/IP profile might need to be modified to reserve the additional ports for z/OS UNIX and the TCP/IP stacks recycled. For information about reserving the additional ports, see z/OS Communications Server: IP Configuration Reference .