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Cannot set "ACE cache forever" for IP lookup in DNS Server

  • 1.  Cannot set "ACE cache forever" for IP lookup in DNS Server

    Posted Tue December 29, 2020 12:49 PM

    Hi all,

    Scenario: 

    • ACE is running on AIX OS.
    • There is a Client (10.0.81.52) calls to ACE'service (10.0.81.53:7800/service/vn/authen/authensvcs/1).
    • There is no entry in both DNS Server and /etc/hosts.
    • To avoid query in DNS Server every time, my idea is using "cache forever" in IBM JVM.

    Action:

    • I configured the java.security:

    networkaddress.cache.ttl=-1

    networkaddress.cache.negative.ttl=-1

    • I used mqsichangeproperties:

    mqsichangeproperties ACE11NODE -e MainServer -o ComIbmJVMManager -n jvmSystemProperty -v "-      Dsun.net.inetaddr.negative.ttl=-1"

    • MainServer was restarted.

    Problem:

    • It seems not to cache the "unsuccessful IP".
    • It still lookup IP in DNS Server.  I captured by using tcpdump:

    Question:

    • Why I have to configure both java.security and mqsichangeproperties ?
    • Why doesnt it work ?

    Thank you very much.



    ------------------------------
    Le Hung
    ------------------------------


  • 2.  RE: Cannot set "ACE cache forever" for IP lookup in DNS Server

    Posted Fri January 08, 2021 11:10 AM
    Hello Le Hung,

    In the tcpdump there´s a query to the reverse DNS lookup and it seems that your DNS do not have a reverse lookup zone. Some applications and tools needs this zone. Your JVM settings has nothing to do with this.

    I hope this can help you.


    ------------------------------
    Francisco A Buccafusca
    Argentina
    ------------------------------

    Original Message


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