Automated Testing

  • 1.  RESOLVER - can not get NSLOOKUP to connect to my routers DNS function from TSO

    Posted Sat January 28, 2023 03:00 PM

    I have the IBM ZD&T Learner Edition, v13.3, installed, but I'm having an issue where I can not get NSLOOKUP to connect to my router's DNS function at 192.168.1.1. I enter, say, 'nslookup www.ibm.com,' but nothing is returned; it just goes back to the TSO ready prompt.

    I have 'NSINTERADDR 192.168.1.1' in the GBLTDATA member in TCPPARMS, and I can ping it okay too.

    Any assistance would be most appreciated.



    ------------------------------
    Mark Regan
    Consultant, z/OS Network Software
    Nationwide Insurance, Retired
    Utica OH
    ------------------------------


  • 2.  RE: RESOLVER - can not get NSLOOKUP to connect to my routers DNS function from TSO

    Posted Mon January 30, 2023 03:36 AM
    egg sucking here Mark,  but did you restart IP/Networking in ZOS after the change?
    I don't have a system in front of me right now,  but know I've had this issue too,  and I may have looked for and changed entries in 'hosts' in /etc in USS also

    ------------------------------
    Rod
    Penarth
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  • 3.  RE: RESOLVER - can not get NSLOOKUP to connect to my routers DNS function from TSO

    Posted Mon January 30, 2023 08:22 AM
    Rod,

    Yes, I did restart TCPIP.

    ------------------------------
    Mark Regan
    Consultant, z/OS Network Software
    Nationwide Insurance, Retired
    Utica OH
    ------------------------------



  • 4.  RE: RESOLVER - can not get NSLOOKUP to connect to my routers DNS function from TSO

    Posted Mon January 30, 2023 01:11 PM
    Well, the issue has been resolved. I took out the entry for 'GLOBALTCPIPDATA(/etc/resolv.conf)' out of my 'USER.Z25A.TCPPARMS(GBLRESOL)' member. Since/etc/resolv.conf was an empty file, it caused RESOLVER not to find an NSINTERADDR statement.

    ------------------------------
    Mark Regan
    Consultant, z/OS Network Software
    Nationwide Insurance, Retired
    Utica OH
    ------------------------------



  • 5.  RE: RESOLVER - can not get NSLOOKUP to connect to my routers DNS function from TSO

    Posted Mon January 30, 2023 01:16 PM
    Great job @Mark Regan - and good to know how you resolved* it

    *pun intended ;)​

    ------------------------------
    Rod
    Penarth
    ------------------------------



  • 6.  RE: RESOLVER - can not get NSLOOKUP to connect to my routers DNS function from TSO

    IBM Champion
    Posted Mon January 30, 2023 09:02 AM
    Mark,

    You might try running wireshark on your linux machine ( running the Learner Edition).

    There could be two problems.   
    1. Your request is not getting out of z/OS
    2. Your request is getting out of z/OS - but the response is not getting back to z/OS

    The  IP Diag reference talks about trace resolver.  This may give you a few clues

    Colin