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Hierarchy Level

Release Information

Statement introduced in Junos OS Release 8.5.

The tenant option is introduced in Junos OS Release 18.3R1.


Specify the Domain Name System (DNS) Application Layer Gateway (ALG) on the device.


  • disable—Disable the DNS ALG. By default, the DNS ALG is enabled. You can enable or disable the DNS ALG for both IPv4 and IPv6 mode.

  • doctoring—Configure DNS ALG doctoring.

    • none— Disable all DNS ALG doctoring.

    • sanity-check—Perform only DNS ALG sanity checks.

  • maximum-message-length—Set maximum message length (bytes).

    Range: 512 through 819.

    Default: 512.

  • oversize-message-drop—Configure to drop the oversized DNS packets.

  • traceoptions— Configure DNS ALG tracing options.

    • flag—Trace operation to perform.

      • all—Trace all events.

      • extensive—Display extensive amount of data.

Required Privilege Level

security—To view this statement in the configuration.

security-control—To add this statement to the configuration.

Related Documentation