I tried to follow the directions of the 
https://www.scientificlinux.org/documentation/howto/upgrade for upgrading to SL 4.1 from 
4, however rpm fails for both statements (4.x and 41):


[root@chrome ~]# rpm -Uvh 
ftp://ftp.scientificlinux.org/linux/scientific/4x/i386/misc/RPMS/yum-conf-4x.SL.noarch.rpm
Retrieving 
ftp://ftp.scientificlinux.org/linux/scientific/4x/i386/misc/RPMS/yum-conf-4x.SL.noarch.rpm
error: skipping 
ftp://ftp.scientificlinux.org/linux/scientific/4x/i386/misc/RPMS/yum-conf-4x.SL.noarch.rpm 
- transfer failed - Unknown or unexpected error

[root@chrome ~]# rpm -Uvh 
ftp://ftp.scientificlinux.org/linux/scientific/41/i386/misc/RPMS/yum-conf-4x.SL.noarch.rpm
Retrieving 
ftp://ftp.scientificlinux.org/linux/scientific/41/i386/misc/RPMS/yum-conf-4x.SL.noarch.rpm
error: skipping 
ftp://ftp.scientificlinux.org/linux/scientific/41/i386/misc/RPMS/yum-conf-4x.SL.noarch.rpm 
- transfer failed - Unknown or unexpected error

[root@chrome ~]#


Any ideas on how to safely upgrade?