lookup {dst-ip|src-ip|dst-port|src-port|uid|jail} N
which searches the specified field in table N and sets tablearg
accordingly.
With dst-ip or src-ip the option replicates two existing options.
When used with other arguments, the option can be useful to
quickly dispatch traffic based on other fields.
Work supported by the Onelab project.
MFC after: 1 week
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