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Re: Fw: IP address for Purdue Suominet site

Hi Myron, 

Beats the heck outta me..

Since this is for form submission, I would be tempted to instruct her to
indicate the exposed IP address, since that is the one we will be dealing
with...I would also have her indicate that the actual suominet machine
will possess a different IP address, and to include that as well. Even
tho' I suspect that the data transfer will be handled by a router behind
the firewall and transparent to us. We may want to remind her that ports
111 and 388 should be open on the exposed host. We should also emphasize
that she should submit her proposal, and if accepted, we can work through
these nuts and bolts once we get up and running....

my .02 cents....

Thanks,

-Jeff
____________________________                  _____________________
Jeff Weber                                    address@hidden
Unidata Support                               PH:303-497-8676 
NWS-COMET Case Study Library                  FX:303-497-8690
University Corp for Atmospheric Research      3300 Mitchell Ln
http://www.unidata.ucar.edu/staff/jweber      Boulder,Co 80307-3000
________________________________________      ______________________

On Tue, 23 Oct 2001, myron mccallum wrote:

> Jeff:
> Do you have an answer for this question from J. Haase regarding a Suomi
> installation
> behind a NAT firewall?  Feel free to answer her directly or to bounce
> through me if you prefer.
> 
> -myron
> 
> ----- Original Message -----
> From: "jennifer haase" <address@hidden>
> To: <address@hidden>
> Sent: Thursday, October 18, 2001 1:54 PM
> Subject: IP address for Purdue Suominet site
> 
> 
> > Dear Myron,
> >
> > I have a question concerning the network connection to our suominet site
> > here at Purdue.
> > The connection is through an ADSL line to our remote site off campus, and
> > connects the site to the university network. There are several computers
> > dedicated to other instruments that will all be connected by the same ADSL
> > line. Our idea was to have a Unix workstation at the site providing a
> > firewall and using the public IP address and connecting the suominet PC to
> > that. In the university network guidelines they say that there is one
> > public IP address associated with the connection, and individual IP
> > addresses to connect the other machines must use Network Address
> > Translation (NAT). it says it is not possible to run a public server (FTP,
> > HTTP, etc) on these subnetwork machines and have it accessible from the
> > Internet. Do you think it will still be possible to run the LDM? Do you
> > know another suomi-net installations that have a similar setup - ADSL to
> > UNIX server/firewall to suominet PC?
> >
> > Is it the NAT subnetwork IP address for the suominet machine that I provide
> > on the suominet form or the IP address of my Unix server/firewall? This is
> > the key question that prevents me sending in my form to get the receiver
> > and PC on their way to me. Our unix firewall has the address:
> > Host: dsl-205-177
> > Domain: resnet.purdue.edu
> > IP Address: 128.210.205.177
> > Subnet Mask: 255.255.255.0
> > Gateway: 128.210.205.1
> > 1st Nameserver: 128.210.11.57
> > 2nd Nameserver: 128.210.11.5
> >
> > Our system administrator is on long term leave because of serious health
> > problems or I would be asking him, though he wouldn't know about LDM.
> >
> > Thanks for any help, and if you know a good tutorial web page for
> > installing such a local network I would appreciate that too.
> >
> > Jennifer Haase
> >
> > ---------------extract from university network
> > guidelines----------------------------------------------
> >
> > In locations where there are three or more computers in a installation
> > location, the Linksys Etherfast Cable/DSL Router is
> > used to provide multiple connections to the network through the 1-Meg
> > Modem.  Due to the fact that the router uses
> > Network Address Translation (NAT), there is only one public IP address
> > associated with the connection.  Subscribers in
> > these locations are issued private IP addresses that begin with "192.168".
> > These addresses are only usable on the
> > private network that is created within your room or apartment by the
> > four-port switch that is built into the Linksys
> > Etherfast Cable/DSL Router.  Therefore, even the first subscriber  must use
> > the router along with
> > the 1-Meg Modem in order to establish a usable connection.
> >
> > In addition to providing multiple connections, the Linksys Etherfast
> > Cable/DSL Router also acts as a firewall between
> > the private network in your room or apartment and the public network.  This
> > feature provides additional security, but as
> > a result, has some limitations as well.  The most notable limitation is
> > that you will not be able to use Microsoft File and
> > Printer Sharing between your computer and your neighbor's computer (other
> > than your  machines on your
> > private network).  Also, since your computer does not have a public IP
> > address, it is not possible to run a public server
> > (FTP, HTTP, etc.) on your machine and have it accessible from the Internet.
> >  The router provides for one exception to
> > this rule:  ONE machine can be set up to use IP address 192.168.xxx.200
> > (where xxx is the subnet number of your
> > private network - usually your building number) which is called the DMZ
> > address.  The router forwards all TCP/IP ports
> > from the public IP address to the DMZ address.
> >
> > ---------------end of extract from university network
> > guidelines----------------------------------------------
> >
> >
> >
> > ______________________________________________________
> > Dr. Jennifer S. Haase
> > Research Scientist
> > Dept. of Earth & Atmospheric Sciences
> > Purdue University
> > West Lafayette, IN 47907-1397, USA
> > Phone number: 1-765-494-1643
> > Department secretary phone number: 1-765-494-3258
> > Department Fax: 1-765-496-1210
> > email: address@hidden
> >
> > "Nature bats last"
> >
> 
>