http://linux1.fnal.gov/linux/scientific/7x/contexts/fermilab/testing/$basearch
http://ftp.scientificlinux.org/linux/scientific/7x/contexts/fermilab/testing/$basearch
http://ftp1.scientificlinux.org/linux/scientific/7x/contexts/fermilab/testing/$basearch
http://ftp2.scientificlinux.org/linux/scientific/7x/contexts/fermilab/testing/$basearch
ftp://ftp.scientificlinux.org/linux/scientific/7x/contexts/fermilab/testing/$basearch