Please remember to use WikiFormatting.
There was a similar report on IRC. The reporter noted it was working again quickly afterwards. I could not see the failure condition myself, as the tarball existed when I checked. Looks like some temporary glitch happened, maybe the mirror was updated at the same time?
$ date
Mon Oct 17 14:48:40 CEST 2016
$ rsync --no-motd 'rsync://rsync.macports.org/macports/release/tarballs/*.tar*'
-rw-r--r-- 27,013,120 2016/10/17 14:01:50 base.tar
-rw-r--r-- 512 2016/10/17 14:01:52 base.tar.rmd160
-rw-r--r-- 64,327,680 2016/10/17 14:01:51 ports.tar
-rw-r--r-- 512 2016/10/17 14:01:52 ports.tar.rmd160