Subject: Virtual Servers

From: Brian Kramer <[email-masked]>
Date: Fri, 12 May 1995 18:48:50 -0400

Is there a way to setup virtual ftp servers?

I'd like to have IP 1.2.3.4 and IP 4.5.6.7 both be on the same physical
machine (which I know how to do), but have 1.2.3.4 (ftp.1domain.com)
and ftp 4.5.6.7 (ftp.2domain.com) appear to be completely different
servers and have different directories.

Anyone doing this?

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From: M BAILEY <[email-masked]>
Date: Fri, 12 May 1995 19:16:01 -0400 (EDT)

> servers and have different directories.
If someone is doing this let me know I would be very interested in how to 
et something like this up.
Thanks

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From: [email-masked] (Russell Street)
Date: Sat, 13 May 1995 12:42:29 +1200 (NZT)

>From the README of the TCP wrappers (archie for "tcp_wrapper").

You can get a package called 'vif' (Virtual Interface) that allows
similiar things on SunOS and HP-UX.  I believe there are also similiar
packages in the works for Linux.

People on SGIs are (for the most part) out of luck, but I believe you
can do hacks with the PPP interfaces to achieve the effect --- check
the FAQ.

You are going to have to edit the code of the two servers to use
different 'ftp' entries in the /etc/passwd file for the different
binaries, of course.

Good luck...
Russell

4.6 - Multiple ftp/gopher/www archives on one host
--------------------------------------------------

Imagine one host with multiple internet addresses. These addresses do
not need to have the same internet hostname. Thus, it is possible to
offer services with different internet hostnames from just one host.

Service providers can use this to offer organizations a presence on the
"net" with their own internet hostname, even when those organizations
aren't connected to the Internet at all.  To the end user it makes no
difference, because applications use internet hostnames.

There are several ways to assign multiple addresses to one machine.
The nice way is to take an existing network interface and to assign
additional internet addresses with the `ifconfig' command. Examples:

    Solaris 2:	ifconfig le0:1 <address> netmask <mask> up
    4.4 BSD:	ifconfig en0 alias <address> netmask <mask>

On other systems one has to increase the number of network interfaces:
either with hardware interfaces, or with pseudo interfaces like SLIP or
PPP.  The interfaces do not need to be attached to anything. They just
need to be up and to be assigned a suitable internet address and mask.

With the wrapper software, `daemon@host' access control patterns can be
used to distinguish requests by the network address that they are aimed
at.  Judicious use of the `twist' option (see the hosts_options.5 file,
`nroff -man' format) can guide the requests to the right server.  These
can be servers that live in separate chroot areas, or servers modified
to take additional context from the command line, or a combination.

Another way is to modify gopher or www listeners so that they bind to
only one specific network address. Multiple gopher or www servers can
then be run side by side, each taking requests sent to its respective
network address.

 -------------------------------------------------------------------
 Russell Street ([email-masked]) +64 (9) 373-7599 extn 6487
   UNIX Systems Programmer, Computer Centre, University of Auckland
	     http://www.auckland.ac.nz/cc/People/RS.html

   Like the blind man in the dark room looking for the black cat
			  that isn't there

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From: [email-masked] (Dan Pritchett)
Date: Fri, 12 May 1995 18:23:21 -0700 (PDT)

> can do hacks with the PPP interfaces to achieve the effect --- check
People on SGI's will do just fine up to 64 virtual hosts. Check out
http://www.thesphere.com/~dlp/TwoServers/ for a description of how to
get multiple interfaces on a variety of platforms.

-- 
Dan Pritchett                               The Sphere Information Services
[email-masked]                           http://www.thesphere.com
(800)664-7434/(408)369-9105                 FAX: (408)266-4376

For my PGP public key, send mail to [email-masked] with
[email-masked] in the message body.

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From: Thomas Leavitt <[email-masked]>
Date: Fri, 12 May 1995 19:12:15 PDT

> You can get a package called 'vif' (Virtual Interface) that allows

Could you point me to a location where I can find "vif" or more information
about it? This is something we are very much interested in.

--
Web Communications (sm)            Thomas [email-masked]
Voice: (408) 457-9671 x101         Lead Systems & Network Admin./Tech Suppt.
 
Web Communications Home Page <URL:http://www.webcom.com/>

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From: [email-masked] (Russell Street)
Date: Sat, 13 May 1995 13:55:10 +1200 (NZT)

> People on SGI's will do just fine up to 64 virtual hosts.

As I said, hacks with the PPP interfaces.  I am sure you are going get
a lot of support from the SGI TAC if any problems came up with doing
this, or it mysteriously stops working after an upgrade.

Comments by Dave Olson (of SGI) in the newsgroups about multiple
addresses on the same interface were not encouraging.

cf, the Solaris 2.x and BSD methods with are officially supported.

> Check out

A most useful resource.

Russell