IT25130: DATAPOWER DNS ROUND ROBIN ALGORITHM DOES NOT HONOR TCP BASED DNSRESPONSE

Fix packs for DataPower Gateway version 7.7
Fix packs for DataPower Gateway version 7.5
Fix packs for DataPower Gateway version 7.5.1
Fix packs for DataPower Gateway version 7.5.2
Fix packs for DataPower Gateway version 7.6

APAR status

• Closed as program error.

Error description

• DataPower DNS Round Robin algorithm will not honor TCP based
  response from DNS server which will cause DNS response to fail
  on DataPower, hence DNS resolution fails.
  

Local fix

• Use First Alive algorithm instead of Round Robin.
  

Problem summary

• DataPower user who uses Round robin as the Load balancing
  algorithm in Configure DNS Settings might see DNS query
  failures.
  
  The following error message might be observed if multiple IP
  
  addresses replied in the DNS query response for Round
  robin DNS:
  Cannot resolve host name '(the Full-Qulified-Domain-Name)' after
  (number of) ms.
  

Problem conclusion

• Fix is available in 7.5.0.16, 7.5.1.15, 7.5.2.15, 7.6.0.8 and
  7.7.1.2
  For a list of the latest fix packs available, please see:
  http://www-01.ibm.com/support/docview.wss?uid=swg21237631
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  DATAPOWER

• Fixed component ID

  DP1234567

Applicable component levels

• R750 PSY

     UP

• R751 PSY

     UP

• R752 PSY

     UP

• R760 PSY

     UP