ONL NPR Tutorial

The ONL NPR Tutorial

NPR Tutorial >> The Remote Laboratory Interface

TOC

RLI Basics

Before beginning our tour of the RLI, let's go over some basic conventions regarding mouse buttons. The following list is a quick summary of the main features:

Menus are accessible by single clicking with the left mouse button.
Objects that have not been allocated have a light blue color.
Allocated objects have a dark blue color.
At all times, hosts and routers have logical names (e.g., host n1p3, NPR.2). After resource allocation, hosts and routers also have actual resource names. For example, onl053.arl.wustl.edu might be the actual n1p3 host. nprcp03.arl.wustl.edu might be the Control Processor (CP) for NPR.2.
Clicking the center of a dark blue icon (allocated object) shows the the actual object's name. In the case of a host, the logical name (e.g., n1p2) refers to the network interface to the internal network (NPR or NSP) and the actual name (e.g., onl053.arl.wustl.edu) refers to the network interface to the external network (an Ethernet). Alternatively, you can use an environment variable like $n1p2 to refer to the external interface. See below for more details.
A single object can be moved to a different part of the window by holding the left mouse button down on the icon and dragging. Components that are close to each other can be moved as a group by dragging a box over the objects to select the objects and then holding the left mouse button down on one of the host icons and dragging.
A property list or menu can be hidden by clicking any open area in the RLI window.
After configuration changes have been made, the changes must be committed by selecting File => Commit. The status box at the bottom of the main display will be outlined in red to remind you that changes have been made and need to be committed before they are actually reflected in the testbed.

These features will be pointed out again as they are encountered.

The /users/onl/.topology File

A user can SSH to onl.arl.wustl.edu (called the login host) at any time but can only SSH into other ONL hosts that have been given to the user as part of the commit process. Control messages and SSH access to a committed ONL host from the login host go over the external (control) network. [[ host-interfaces-resize.png Figure ]]

Every host given to a user as part of the commit process has two interfaces: one connected to the internal (private) testbed network and one connected to the external (control) network. Experimental traffic goes over the internal network consisting of your routers and the interconnection switch. The figure (right) shows one NPR with two hosts. Each host has been annotated with green bars depicting the network (Ethernet) interfaces to the two networks and red lines depicting the control network.

Throughout our descriptions in the NPR Tutorial, interface names that begin with a dollar sign (e.g., $n1p2, $n2p3) refer to the Ethernet interface that is connected to the control network. You should replace those symbols with the hostnames appropriate to your setup or run the source Unix command shown below to make these symbols meaningful.

Interfaces to the internal network have IP addresses of the form 192.168.N.H where N is the logical router number and H is the host portion and have names such as n1p2, and n2p3 (Note: not $n1p2 or $n2p3); i.e., omit the dollar sign when referring to the internal network interface. For example, if you ask for only one router, the value of N will always be 1. But NPR 3 might be the actual router. If you ask for two routers, N will be 1 for one router and 2 for the other router. Interfaces to the external (control) network have IP addresses of the form 10.0.0.H where H is the host portion and have names such as onl062.arl.wustl.edu (which has the short name onl062). These external names are determined during the commit phase when actual resources are bound to resources in your configuration.

In many cases (especially scripts), it might be easier to refer to the environment variable (e.g., $n1p2) associated with the external interface whenever you are refering to the control network interface. These variables can be imported into your environment by running ONE of these two commands (your choice will depend on your ONL shell):

     source ~onl/.topology		# bash
     source ~onl/.topology.csh		# csh, tcsh

By default, users are assigned the bash shell. Enter the ps command to identify which shell you are running. Note: The control network interface names in the environment variables are NOT automatically defined.

You can verify that this procedure has worked by enterring something like:

     printenv n1p2
     echo "$n1p2"

which should display an external name of the form onlXXX (e.g., onl062, onl053) in both cases.

Revised: Tue, Aug 26, 2008

NPR Tutorial >> The Remote Laboratory Interface	TOC