Manual Chapter : Default DAG

Applies To:

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  • 17.1.0, 17.0.0, 16.1.4, 16.1.3, 16.1.2, 16.1.1, 16.1.0, 16.0.1, 16.0.0, 15.1.10, 15.1.9, 15.1.8, 15.1.7, 15.1.6, 15.1.5, 15.1.4, 15.1.3, 15.1.2, 15.1.1, 15.1.0, 15.0.1, 15.0.0, 14.1.5, 14.1.4, 14.1.3, 14.1.2, 14.1.0, 14.0.1, 14.0.0, 13.1.5, 13.1.4, 13.1.3, 13.1.1, 13.1.0
Manual Chapter

Default DAG

The Default DAG uses a hash of source and destination port. It is useful when ephemeral ports are used in client side and server side connections. When source and destination ports are the same TMM-0 will be used. This is an issue in that the traffic will not be load balanced and TMM-0 will quickly be overloaded. This DAG requires randomness in the source or destination port. If a client doesn't specify a source port then an ephemeral port will be used and Default DAG will work properly. Note, the ephemeral port must increment randomly or by single digits. If it's incremented by an even number, such as two, or by the number of TMMs then it's possible that it will hash to the same TMM or a small set of TMMs, which will negatively impact BIG-IP performance.

Key Points

  • Port Based.
  • Works best when clients use ephemeral ports.
  • Can work with 1 to n clients.
Default DAG example
Default DAG example