Automated Testing

  • 1.  ZD&T and IPV6

    Posted Wed June 22, 2022 12:53 AM
    Has anyone configured z/OS running on ZD&T to support IPV6 protocol?
    With IPV4 there was a need to define a static route in the router between the z/OS IP address and the Linux host IP address.
    I don't see any option in my router to define an IPV6 static route.  so is this a deal breaker for using IPV6 ?

    Dan Kalmar

  • 2.  RE: ZD&T and IPV6

    Posted Thu June 23, 2022 03:22 AM
    Just as an experiment I gave it a try although I believe that it hasn't been fully tested nor supported from an IBM side. I'm not a network person and forgot to make copious notes but this is basically what I did, and it worked!

    Prefix/L: fd
    Global ID: a2d76ba0d9
    Subnet ID: 5d6d
    Combine/CID: fda2:d76b:a0d9:5d6d::/64
    IPv6 addresses: fda2:d76b:a0d9:5d6d::/64:XXXX:XXXX:XXXX:XXXX
    Start Range: fda2:d76b:a0d9:5d6d:0:0:0:0
    End Range: fda2:d76b:a0d9:5d6d:ffff:ffff:ffff:ffff
    No. of hosts: 18446744073709551616

    • So from that I configured my system as:
     Linux: fda2:d76b:a0d9:5d6d:0:0:0:a190
    zOS: fda2:d76b:a0d9:5d6d:0:0:0:a191
    IPv6 Gateway: fda2:d76b:a0d9:5d6d:7eff:4dff:fef1:f402/64
    DNS: fda2:d76b:a0d9:5d6d:7eff:4dff:fef1:f402
    Windows10: fda2:d76b:a0d9:5d6d:0:0:0:a195


    • Next you have to enable the IPv6 stack in z/OS and I enabled both IPv4 and IPv6 with the following in BPXPRM00




    • Then there is the TCPIP PROFILE and my working one looks like this:


    ;This device defines the tunnel  - TAP and this is still IPv4                                        
    DEVICE PORTA  MPCIPA                                                    
    LINK ETH1  IPAQENET PORTA                                               
    HOME ETH1                                                      
    ; This second device is optional   - this is for direct connectivity notice that we use INTERFACE now                                      
    INTERFACE MPCIPA ; OSA QDIO                                             
    DEFINE IPAQENET6                                                        
    PORTNAME PORTB                                                           
    IPADDR fda2:d76b:a0d9:5d6d:0:0:0:a191                                   
    ;     Destination       SubnetMask   FirstHop       LinkName  Size      
    ROUTE fda2:d76b:a0d9:5d6d:0:0:0:a190 HOST =      MPCIPA  MTU 2000       
    ROUTE           =          ETH1 MTU 1492          
    ROUTE DEFAULT6 fda2:d76b:a0d9:5d6d:7eff:4dff:fef1:f402 MPCIPA MTU 1492  
    ITRACE OFF                                                              
    IPCONFIG NODATAGRAMFWD                                                  
    IPCONFIG6 NODATAGRAMFWD                                                 
    UDPCONFIG RESTRICTLOWPORTS                                              
    TCPCONFIG RESTRICTLOWPORTS                                              
    TCPCONFIG TTLS                                                           
    START PORTA                                                             
    START MPCIPA                                                            


    And that was basically it however there are a couple of problems


    • I don't have an IPv6 capable 3270 emulator so I had to use x3270
    • it looks like TAP doesn't support IPv6 using the –tunnel_ip statement so I've left that as a 10.* one for the moment, anyway, it's only internal to Linux and zPDT


    Sebastian Welton

  • 3.  RE: ZD&T and IPV6

    Posted Thu June 23, 2022 12:17 PM
    Thanks for the detailed response.
    With IPV4 I recall I had to define a static route in the router between the z/OS internal IP to the Linux internal IP.
    Is this still required for z/OS to connect to WAN locations ?

    Dan Kalmar

  • 4.  RE: ZD&T and IPV6

    Posted Fri June 24, 2022 03:36 AM
    I have never done anything with my router for ZD&T or zPDT. I primarily follow the various scenarios in the Redbook and configure a TAP address for Linux --> guest use and an external IP address for direct connectivity to the guest systems.


    Sebastian Welton