Accessing Files From Off-Grounds
If you are trying to access files from an off-grounds location, there are
multiple ways for you to do so.
Why do you need to do any of this?
In the summer of 2003, ITC began filtering TCP traffic on port 445 in
response to an onslaught of worms that propagated through this port. Their
firewall works by checking the IP address of incoming traffic. If the
address falls within our netmask (128.143.XXX.xxx), then the computer is
allowed access on port 445. When you try to connect from an outside
computer, the IP address will not match the 128.143 netmask, and you will
be blocked from accessing files on the UVA network.
To get around these blocks, there are a couple different options:
SecureFX®
This is a GUI based Windows application that will allow you to access your
files. From the ITC site: "A simple FTP protocol is insecure, since it
transfers files as plain text in ASCII mode or a stream in binary.
SecureFX® encrypts the login i.d./password combination and other
content into meaningless gibberish so that it cannot be read in transit over
the Internet. SecureFX® supports multiple concurrent transfers,
server-to-server transfers, and site synchronization (under certain
conditions), in both binary and ASCII modes." Visit the
ITC Web page to download it if you do not already have it.
Along with the installation file you will find instructions on how
and when to use it.
This is a good option to use if you would like to transfer an entire file
to your computer, if you would like to work on a file without moving its
location, look at the CIFS option listed below.
SFTP / SCP
Secure File Transfer Program and Secure CoPy are two file transfer options
that come pre-installed on Unix boxes. With SFTP and SCP your password is
encrypted through a channel based on the ssh communication protocol. All
commands and processes that occur as "children" of the connecting process
are all protected by this same channel. This protection lasts as long as
the "parent" process is active.
These are the Linux version of SecureFX.
SFTP/SCP can be invoked by typing sftp or scp at any UNIX/Linux prompt
respectively. SCP, for example, is very useful because you can copy
files from one machine to another:
adder:/ ; scp host1:file1 host2:file2
So, if you want to copy a file from the temporary directory on
whirlwind.cs.virginia.edu to your home directory:
adder:/ ; scp whirlwind.cs.virginia.edu:/tmp/filename host:filename
Typing man scp or man sftp will give more information about
using these commands.
CIFS
The Common Internet File System is another way that computer users can
access files from outside the system. The University's CIFS is known as
UVA-Anywhere, and involves using a Virtual Private Network (VPN).
Within the VPN, you want to use the UVA-Anywhere profile. UVA-Anywhere
gives your remote computer a UVA IP-address by using a NAT (Network
Address Translation) box. Your remote computer is then allowed to gain
access to UVA's servers, as if you were working from an on-grounds
computer. For security purposes, the information being transferred
is encrypted by the VPN client.
Visit the ITC web page to register for
UVA-Anywhere.
This will take you through a multi-step process which will set you up with
a UVA-Anywhere account. This account can then be used again and again when
you are trying to access the UVA network.
The drawback to using UVA-Anywhere is that the bandwidth requirement is
somewhat high. If used during off-peak times this should not create
too much of a problem.
