What is the aim of KivaNS?

KivaNS is mainly a simulation application to simulate how IP routing works. To do it, KivaNS not only allows user to design and draw a network scheme with a graphical interface, but also it allows to configure the equipment drawn and finally simulate the transmission of data from a host to another. It is possible configure interfaces, routing tables and other parameters in a similar way to the real equipment. The main target of KivaNS is the education and learning of data networks topics, but the application can be also used to dazing and verify routing tables for real networks. In addition, the KivaNS’s API (Application Programming Interface) can be use to include network simulation in other Java applications.

Does KivaNS use and graphical interface or is it an API?

KivaNS offers the two ways of working for simulating networks because it is composed of two well differentiated blocks: a low level API (Application Programming Interface), and a high level graphical user interface. The firs one allows programmers to include network simulation capabilities in their Java applications. The second one is an easy and compressive user interface which no requires programming.

What is the knowledge required to use KivaNS?

Because KivaNS is a data network simulator, user should have a basic knowledge about network working: architecture layers, link and network layers protocols, TCP/IP architecture, etc. In addition, knowledge about IP addressing and routing, as well as knowledge about configuration of routing tables, are recommended.

Does KivaNS for MS. Windows or for Linux/Unix?

KivaNS is programmed in Java and, thus, it is no targeted to a specific platform. Because this, it works on different operating systems such as MS. Windows or Linux. The only requirement is to have the JRE (Java Runtime Environment) installed before in the computer. In addition, to make programs with the API, it is necessary the JDK (Java Development Kit). It is recommendable the version 1.4.2 or higher for the JRE and SDK. This libraries cab be downloaded form the Sun’s web.

In order to easily execute the graphical interface on a Linux/Unix system, the file used to execute the application on MS. Windows (KivaNS-start.bat) can be changed for a text script (my_script) file whit the following content:

#!/bin/bash
export CLASSPATH=".:Simulador.jar"
java visual

The file should be saved in the folder where the archive "Simulador.jar" is. Then, it is neccesary to ennable it for execution with the command "chmod", and finally, the applciation can be started as follows::

chamod +x my_script
./my_script

¿How KivaNS can be compiled on Linux?

For example,to compile the graphical interface of KinaNS, an script like the following can be used:

#!/bin/bash
find /home/myuser/Kiva -iname "*.class" -exec rm {} \;
javac -classpath /home/myuser//Kiva/:/home/myuser/Kiva/Simulador.jar -Xlint:unchecked visual.java

It is recommended to utilize the package with the sources of the graphic interface of the version 1,1 for Linux available in the section of software, thus, in these sources, some aspects that gave problems when compiling in Linux have been corrected.

Is it possible to use subnets?

Yes, it is possible to define and use subnets. The masks are used like in real equipment. Although the mask for an IP is completed automatically in the configuration dialogs, a new mask for a subnet can be indicated.

¿What do the 0.0.0.0 entries of tjhe routing table mean?

In the same way that in some real equipment, a routing table can list entries with the gateway 0.0.0.0. These entries reference the destinations which are directly conected to the host and, thus, they no require a gateway. In contrast, the OS. MS. Windows the gateway for these entries would be the IP address of the one of their interfaces.The entries 0.0.0.0 are added automatically when a new interface is added to the host.

¿Por qué algunos elementos o redes no funcionan?

Algunos equipos o redes que se pueden dibujar no tienen simulación asociada. En la versión 1.0 se pueden simular solo las redes ethernet en bus, y conexiones punto a punto, interconectadas con routers. En la vesión 1.1. se pueden usar además conmutadores y ethernet conmutadas.

When the graphical interface is executed in Linux, the windows are empty and they do not have any controls.

A aspect to be beared in mind is that swing and awt environments of Java can cause some problem when a Java graphical application based on these environmets (this is the case of KivaNS) is executed on windows managers like Compiz/Beryl. In this situation, the windows are contructed, but their controls are not shown, and Java adverts something like "It is not possible to change the interface". The solution is to disable the esmerald window decorator and use the default manager (i.e. metacity, the default window manager of GNOME).