Manual Chapter : Source port

Applies To:

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BIG-IP LTM

  • 15.1.0, 15.0.1, 15.0.0, 14.1.2, 14.1.0, 14.0.1, 14.0.0, 13.1.3, 13.1.1, 13.1.0
Manual Chapter

Source port

MRF allows setting the source port used on outgoing connections through the source-port attribute of a transport-config object. Setting this attribute to a non-zero value causes the source port of the outgoing connection to be set to the provided value. If set to zero an ephemeral port value will be used.
Pinning the source port to a fixed value will limit the number of connections available to the host. There can only be one connection using the local and remote tuples (IP/port/rtdom_id) and IP protocol (TCP/UDP/SCTP). Attempts to create another connection using the same addresses and IP protocol will fail.
For this reason it is not recommended to use set the source port for outgoing connections except when using a connection-mode of 'per-peer' and a number-connections of '1'.
Likewise trying to use the same host from peers with different transport settings (transport-config and/or virtual) and setting the source port will produce failures (unless different SNAT pools are used).