[tex-live] rsync?

[Bob Tennent]

Now trying to use rsync to download the whole directory (and
then update it incrementally if there are size errors).

Neither the syntax at the tlpretest site nor the syntax in
man rsync work:

rsync -a --delete --exclude="mactex*" ftp.math.utah.edu:texlive/tlpretest tlpretest/

asks for my password.

rsync -a --delete --exclude="mactex*" rsync://ftp.math.utah.edu::texlive/tlpretest tlpretest/

says

ssh: Could not resolve hostname rsync: Name or service not known.

rsync -a --delete --exclude="mactex*" rsync://ftp.math.utah.edu/texlive/tlpretest tlpretest/

says

rsync: failed to connect to ftp.math.utah.edu (155.101.98.136): No route to host (113)

whereas 

ping ftp.math.utah.edu

works fine.

Do I need to specify a non-standard port or a specific user?  

Bob T.