como DanR declarou no comentário, dê uma olhada no arquivo /opt/local/etc/macports/sources.conf
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# To get the ports tree from the master MacPorts server in California, USA use:
# rsync://rsync.macports.org/release/ports/
# To get it from the mirror in Trondheim, Norway use:
# rsync://trd.no.rsync.macports.org/release/ports/
# A current list of mirrors is available at https://trac.macports.org/wiki/Mirrors