Tim, Thanks for all your suggestions. I did not know the CTC option was still available. Since the CTC are configured and not really used, I will use this approach for now until I get the Network team to investigate the issue with the switch. I will also review option #2 when I have some free time. I think that is the way I would like to go since configuring Hiper Sockets doesn't seem to be option for this CPU.
-----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Timothy Sipples Sent: Monday, October 2, 2023 11:02 PM To: [email protected] Subject: Re: SNA Link Replacement in Z/OS 2.5 Charles Hights wrote: >I am trying to find a replacement for SNA Link in Z/OS 2.5. My problem, >I have >4 LPAR's on one physical CPU. Normally to IP between the LPAR's we >would just FTP to that LPAR's IP address and we had no issue. Now all >of sudden the traffic is timing out. My routes are very simple, just a >default route that sends everything to the switches that the OSA's >connect to. I have spoken to the Switch support team and they say since >the mainframes are on the same IP Segment it is not being passed to the >FW. Unfortunately the switch team doesn't have any tools that will show >what is happening to the traffic once the switch gets it. So I wanted >to bypass the switches and setup an SNA Link type replacement. I see >that feature is not defined in Z/OS 2.5. On another client we use Hiper >Sockets to bypass the switches for internal IP between the LPAR's. On >this particular CPU, Hiper Sockets devices are not configured in the IO >Gen. So is there something in Z/OS 2.5, besides Hiper Sockets, that support a >device and link type statements to all traffic between LPAR's on the same CPU? Obviously you should try to solve the extant networking problem. If your network switches are misconfigured that'd be bad. In the meantime/in addition, you have options (examples): 1. Yes, you can configure HiperSockets. You can also pair HiperSockets with SMC-D connections - and you should if your machine model supports SMC-D. SMC-D was introduced in z/OS 2.2 (with PTFs) and on the IBM z13 family of servers (with a firmware update). 2. If your z/OS LPARs are configured to share one or more OSA-Express ports, and if they are otherwise suitably configured, then traffic can hop from stack to stack via OSA-Express but without flowing through the network switch. See here for the entry point into the z/OS 2.5 documentation on that subject: https://www.ibm.com/docs/en/zos/2.5.0?topic=attachment-osa-express-port-sharing In short, make minor adjustments to your routing if you're sharing OSA ports. Then that should take the switches out of the loop. 3. I think it's still possible to configure TCP/IP connections over CTC (IPv4 only) or XCF. If you happen to have CTC or XCF connectivity between z/OS LPARs then that's an option, albeit a little "off the beaten path" these days. 4. If you have at least one OSA-Express 1000BASE-T adapter with port (X) available to z/OS LPAR (X) and port (Y) available to z/OS LPAR (Y) then I suppose you could connect a cable directly between ports, bypassing any network switches. IBM doesn't necessarily recommend this, and you might need a crossover cable (depending on how the OSA-Express adapters are configured). Can you also do this for fibre cables? I don't know; I've never tried it. ----- Timothy Sipples Senior Architect Digital Assets, Industry Solutions, and Cybersecurity IBM zSystems/LinuxONE, Asia-Pacific [email protected] ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
