Advanced Network Configuration
------------------------------

If you will be setting up Envoy in a complex network (i.e. one with more than
one physical network), there are many issues that must be taken into account
that are not feasible to cover in detail in this manual.

The biggest of these issues are addressing, routing, and subnetting.  Addressing
is the scheme by which machines on a network are assigned a unique network
number or network address.  This scheme various from one protocol to another.
The scheme used by Envoy for addressing is defined by the Internet Protocol,
an international standard for computer networks.  The Internet Protocol (IP)
states that each machine on a network using IP must have a unique 32-bit (4 byte)
number assigned to it.  This number is used to identify which network a machine
is located on, as well as to uniquely identify the machine on that network.

Two other issues, routing and subnetting, are also closely related to
addressing.  Routing is the means by which data from one computer network
is delivered to another computer network.  Most machines on a network using
the Internet Protocol store a table in memory of ways to find other networks.

Subnetting is a method that is commonly used when creating a network that
will have many different pieces, such as a network installed in a large
building or at a University.  If affects how a machine's network address is
assigned, as well as how a machine's routing tables must be set up.

If your site is already connected to the Internet or already has a large
network installed that is using the Internet Protocol (or IP), contact your
network administrator about assigning an IP network address for your machine.
If your machine will need special routing tables, or if your network is
subnetted, your network administrator will be able to help you.

If your site does not already have a network installed that is connected
to the Internet, or does not use the Internet Protocol, we suggest that you
purchase a book that discusses issues such as addressing, routing and
subnetting when using the Internet Protocol.  Appendix B has a list of good
books that describe the Internet Protocol, and other books related to computer
networking in general.


Configuring envoy for use on complex networks.
----------------------------------------------

When Envoy is installed, you will be given a choice of what kind of
network you will be using.  The two choices are Simple and Internet.
If you will not be using Envoy in a situation where your network
is part of the Internet, or your network does not have more than
one section, you may choose the Simple option.

If you choose the Internet option, there are certain pieces of
information that the Installer will ask you for.  Most of this
information should be provided to you by your network administrator,
or by whoever will be in charge of the Envoy network at your site.

Machine Name:  This may be anything you wish, so long as there
	       are no other machines in your Realm (discussed
	       below).  Machine names are limited to 31 ASCII
	       characters. The only limitation is that the
	       name may not contain a colon (:) character.

Network Address: This should be the Internet Address that will
		 be used by your machine.

Subnet Mask: If your network is subnetted, you will need to know
	     the subnet mask for your network.

Default Router Address: If the piece of the network you are on
			only has a single router attached to it,
			you may enter that router's address at
			this time.  Otherwise, you should use
			the Network Configuration utility to
			configure the routing tables for your
			machine.

Realm Name: This should be the name of the Realm your machine will
	    be in.  This is an ASCII name such as Marketing,
	    Sales, Engineering, etc.

Realm Server Address: This must be set to the network address of
		      the machine acting as the server for your
		      Realm.

If you make a mistake at any time during the installation process,
you may either start over, or you may change any of the information
you gave during the install script using the Network Configuration
tool installed in the Envoy Configuration drawer.



What is a Realm?
----------------

I realm is a collection of one or more physical networks that are
set up to act as one logical network.  This is done by having a
single machine extend NIPC's inquiry capabilites to multiple
physical networks.

To accomplish this, the machine that is to be designated as a
Realm Server has to be provided with a list of the network addresses
of all networks within a Realm.  Consider the diagram below.


Backbone Network (137.239..10.0)
----------------+-------------------------------+-------------------
		|				|
		|				|
		+- Harley (137.239.11.2)        |
		|                               |
      Kawasaki -+				+- Chrysler (137.239.12.3)
		|                               |
		+- Yamaha              Pontiac -+
		|                               |
	 Honda -+                               +- Saturn
		|                               |
		|                               |
		|                               |
		|                               |
		|                               |
		|                               |
		|                               |
		|                               |
	Subnet (137.239.11.0)		Subnet (137.239.12.0)


On this network, a subnet mask of 255.255.255.0 is beging used, so
that the first three bytes of the IP address are used to designate each
physical network.

If you wanted the two networks 137.239.11.0 and 137.239.12.0 to act as a
single Realm named Vehicles, you would choose a machine to act as the
Realm Server.   This machine may be on either network, or may even be
on a different network altogether, as long as all of the machines on
both networks are able to communicate with it.  For simplicity, we'll
choose Harley to be the Realm Server.

To configure this, you will first need to run the NIPC configuration
utility on Harley.  Swith to the Realm Configuration panel, where you
will see two listview gadgets.

What you would need to do is add two entries to the lefthand listview
with the following information:

	Vehicles 137.239.11.0
	Vehicles 137.239.12.0

"Vehicles" should be entered into the lefthand string gadget, and
the network addresses should be entered into the rightand string
hadget.

Now, for each machine on both networks, you must run the NIPC configuration
program, and on the first panel, set the Realm Name to "Vehicle" and the
Realm Server Address to 137.239.11.2.  (This should also be done on Harley).

The Remote Realms listview is used for informing a Realm Server of Realms
that are being controlled by other machines.  For example, if you had a
third network with an address of 137.239.13.0 and wanted to have it called
"Boats", you could add an Entry to the Remote Realms listivew similar to
the following:

	Boats	 137.239.13.5

Where 137.239.13.5 is the IP address of the machine that is controlling the
Boats Realm.  Likewise, that machine should have an entry for "Vehicles"
in it's list of Remote Realms that looked like this:

	Vehicles 137.239.11.2

Where 137.239.11.2 is the address of Harley.





The Envoy Network Configuration Tool
------------------------------------

For most systems, it will not be necesssary to use this tool.  If,
however, you will be setting up a machine with multiple network
interfaces or would like to modify some aspect of your machine's
configuration, you will need to use it.

When the Network Configuration Tool is run, it will open a window
that will display information such as the machine's name, and
who the machine's owner is.

In the upper right of the window, there is a checkbox that is
used to configure whether or not Envoy is using Realms or not.
This should be turned on if you are on a complex network.

If the "Use Realm Server" button is checked, you will also
see another checkbox gadget and two additional string gadgets.
The second checkbox gadget is used to configure whether or not
a machine will be used as a Realm server, and should normally
be left off.

The two additional string gadgets are used for setting a machine's
Realm name and for setting the network address of the Realm Server
for that Realm.

By clicking on the Cycle gadget in the upper left hand portion of
the window, you may switch to the other configuration panels.

--

The second configuration panel is used to configuring what network
interfaces are connected to a machine. The listview on the lefthand
side of the window displays all of the devices that have been added
to Envoy's list of known interfaces.  There are two buttons below
the listview that are used for adding or removing devices from the
list.

On the righthand side of the window are a number of string and
intefer gadgets (some with default checkbox gadgets) that are used
to set up such things as the network address, subnet mask, hardware
address, etc. for each device.  These are:

IP Address:  This gadget is used to set the network IP address for
	     a particular network interface.

Subnet Mask: This gadget is used to set the subnet mask for a
	     particular device if subnets are being used.   If
	     subnets are not being used, the "Use Default" box
	     should be checked.

Address: This gadget is used to set or override the hardware
	 address for a network interface.  This is a very advanced
	 option, and should rarely need to be used.  "Use Default"
	 should be checked.

IP Type: This integer gadget is used to set the packet type for
	 IP packets on a device. The configuration editor knows
	 the defaults for ArcNet and Ethernet.

ARP Type: This integer gadget is used to set the packet type for
	  ARP packets on a device.  The configuration editor knows
	  the defaults for ArcNet and Ethernet.

Unit: This gadget is used for choosing which unit of a device to
      use.  For example, a machine with two Ethernet cards would
      need two entries, one with Unit 0 and one with Unit 1.

Status: This gadget allows a user to temporarily disable a network
	a network interface without having to delete the entry.

--

The third panel is used to configure the routing table used by
Envoy.  The listview contains a list of destination/gateway
pairs.

An existing route may be edited by clicking on it and editing
either the destination or gateway below the listview.

A new route may be added by clicking on the "Add" button. An
existing route may be deleted by clicking on the route and then
clicking on the "Delete" button.

--

