Re: setting IP address(es) and gateways on IBMi LPAR at IPL time based on server serial number?

Le 30/10/2021 à 11:13, Laurence Chiu a écrit :

It was mentioned that the production LPAR could have two IP stacks created,
one for the production site and one for the DR site. Then on IPL the
startup script could interrogate the serial number of the server it was
running on and implement the appropriate IP stack. That sounds like the
right answer but we don't have the expertise or knowledge to know how to do
that.

First of all set up IP interfaces (not stacks) not to automatically start. Review AUTOSTART parameter of CHG(ADD)TCPIFC command.

You can setup gateways to specify preferred interfaces, so that they are used only when on the appropriate site. Review CHG(ADD)TCPRTE command and its BINDIFC parameter.


Then, in the startup program (the one in QSTRUPPGM system value), before starting any service of sub-system, add a couple of lines as below:


Retrieve serial number from QSRLNBR system value (RTVSYSVAL command)

If serialnumber = siteone, start IP interface of siteone with STRTCPIFC command (I would suggest to use an alias here in place of the IP itself)

if serialnumber = sitetwo, start IP interface of sitetwo still with STRTCPIFC command

if serialnumber = an unexpected value, do nothing and report a message to QSYSOPR


Another approach would be to use a dhcp server to provide IP address (review *IP4DHCP special value of INTNETADR parameter of CHG(ADD)TCPIC command), and make sure that the dhcp and dns servers of the enterprise are properly set so that dns is updated on an automatic way from dhcp.