>>
As someone else pointed out, you can have multiple servers running on 
the same machine. Each service has a standard port (port 21 for ftp, 
port 22 for ssh, port 23 for telnet, port 80 for HTTP, port 443 for 
HTTPS.
<<

Yes, of course, I just mean I'm not going to be able to drop ftp.

Thanx,
A. Jorge Garcia
http://calcpage.tripod.com

Teacher & Professor
Applied Mathematics, Physics & Computer Science
Baldwin Senior High School & Nassau Community College


-----Original Message-----
From: Dr. David Kirkby <david.kir...@onetel.net>
To: sage-support@googlegroups.com
Sent: Wed, Nov 18, 2009 6:04 am
Subject: Re: [sage-support] Re: Server Wars!

calcp...@aol.com wrote:
> Well, I use the ftp site to share files with my students (pdfs, mp4s,
> assorted apps, etc).  So, I think I need a dedicated ftp server after
> all....
>
> *HTH,
> A. Jorge Garcia
> http://calcpage.tripod.com <http://calcpage.tripod.com/>
>
> Teacher & Professor
> Applied Mathematics, Physics & Computer Science
> Baldwin Senior High School & Nassau Community College*
I'll make a few comments on various points made by others on this 
thread.

As someone else pointed out, you can have multiple servers running on 
the same
machine. Each service has a standard port (port 21 for ftp, port 22 for 
ssh,
port 23 for telnet, port 80 for HTTP, port 443 for HTTPS. Sage uses 
port 8000 by
default).

There are 2^16 -1 ports, so in principle you could have 2^16 -1 
different types
of servers running, or 2^16 -1 servers of the same type running on 
different ports.

Except in cases where the highest levels of security are needed, or the 
amount
of traffic is very high, it would be a huge waste of resources to 
dedicate one
physical computer to each of these. Just run all services on the one 
bit of
hardware.

There is no anonymous ftp equivalent for SSH. The whole idea of secure 
shell
(SSH) is to provide a very high level of security. The whole idea of 
anonymous
ftp is you let anyone get the data. The two are as different as chalk 
and cheese.

The fact the standard Sage server uses HTTP, does not prevent you 
running a
normal web server on the same machine too, as long as they use 
different ports
(80 and 8000 are different of course).

In fact, Apache allows you to run multiple web sites, all on the one 
server,
using the same port, using something called a 'VirtualHost'.

Things get more complex when security is more of an issue. Allowing 
root access
via via telnet or ftp is a particularly bad idea.

Instead of anonymous ftp, if students need to get at files, I'd just 
stick them
in a directory where Apache servers files from. That's more convenient 
than ftp
for most people, as they can use a browser.

You can browse my files here

http://sage.math.washington.edu/home/kirkby/Solaris-fixes/

despite the fact other parts of

http://sage.math.washington.edu/

are more typical of what you see on a web server.

If you want students to upload data, I would give them accounts on a 
machine
with an ssh server and tell them to use ssh. Whilst uploading can be 
done via a
web site, it is in my opinion not as secure and is a lot more hassle to 
implement.

In any case, getting students to use ssh is no bad thing. It will 
introduce them
to something which they might not have used before and is actually very 
useful.

Dave



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