**3.2. RIPv1-RIPv2 compatibility—practical example**

Devices that implement RIP version 2 can either broadcast datagrams or multi-cast them. In the broadcast situation, devices that implement RIP version 1 can intercept transmitted messages and even respond to them, but because they were not configured to intercept multicast messages, they will not interact with multi-cast transmitted datagrams [14].

In order to utilize and highlight the above information, the following hypothetical situation will be presented and analysed using the HypeRSimRIP application:

A medium-sized company decides to hire a network administrator to create and ensure the maintenance of a network system inside their building. Assuming that the building has four floors and that on each floor there are two terminals (computers-hosts).

To ensure a good connectivity, the administrator will design a star-type topology (see Figure 6); on each floor, he will install a router, to which the respective two terminals will connect, and the four routers will inter-connect through a fifth router, which will provide the external network (e.g. Internet) connection. Obviously, to ensure full control of the corporate network, the administration terminal will be connected to this central router.

Thus, having designed the network, the administrator will continue by assigning the IP addresses provided by the Internet Service Provider (ISP), based on the sub-net mask and the requirements of the physical topology—suppose that the address is 192.168.0.0 with the standard mask /24 (255.255.255.0) (see Figure 15).

According to the VLSM technique of the HypeRSimRIP application, the administrator can now configure all routers with their corresponding parameters (static IPv4 addressing, for better security) (see Table 2). Finally, the network becomes operational (see Figure 16).

**Figure 17.** Highlighted routes: (a) from H1 to the central router and (b) from H3 to the central router.

**Figure 16.** Online network.

Most of the values during the update periods remained at 17.136 bps (10 times less than the minimum usage boom from the without randomization simulation), and in just a few excep‐ tions, the network usage reached 51.408 bps (still half the minimum usage boom from the

Proceedings of the International Conference on Interdisciplinary Studies (ICIS 2016) - Interdisciplinarity and Creativity

In conclusion, because the transmissions are distributed, the network is not anymore disrupted

Devices that implement RIP version 2 can either broadcast datagrams or multi-cast them. In the broadcast situation, devices that implement RIP version 1 can intercept transmitted messages and even respond to them, but because they were not configured to intercept multi-

In order to utilize and highlight the above information, the following hypothetical situation

A medium-sized company decides to hire a network administrator to create and ensure the maintenance of a network system inside their building. Assuming that the building has four

To ensure a good connectivity, the administrator will design a star-type topology (see Figure 6); on each floor, he will install a router, to which the respective two terminals will connect, and the four routers will inter-connect through a fifth router, which will provide the external network (e.g. Internet) connection. Obviously, to ensure full control of the corporate network,

Thus, having designed the network, the administrator will continue by assigning the IP addresses provided by the Internet Service Provider (ISP), based on the sub-net mask and the requirements of the physical topology—suppose that the address is 192.168.0.0 with the

According to the VLSM technique of the HypeRSimRIP application, the administrator can now configure all routers with their corresponding parameters (static IPv4 addressing, for better

security) (see Table 2). Finally, the network becomes operational (see Figure 16).

significantly by the RIP datagrams, thus avoiding a possible network overload.

cast messages, they will not interact with multi-cast transmitted datagrams [14].

will be presented and analysed using the HypeRSimRIP application:

floors and that on each floor there are two terminals (computers-hosts).

the administration terminal will be connected to this central router.

standard mask /24 (255.255.255.0) (see Figure 15).

**3.2. RIPv1-RIPv2 compatibility—practical example**

previous simulation).

**Figure 15.** IP range window.

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Now, the administrator's design choice becomes obvious; any malicious information, any informatics attack that comes from the exterior, from the supernet, will be first intercepted by the administrator and dealt with. By using the route highlight facility of the program, the above-mentioned can be proven (see Figure 17).

By looking at Figure 18, it can be observed that any data package transmitted between two different floors will be routed through the central router. Thus, the administrator will have direct access to all the data transmitted inside the building. Such a perspective may have undesired consequences, such as the creation of direct routes between directly connected floors (to bypass the central router), which are undesired by the administration (see Figure 19).

**Figure 18.** The route from H8 to H5 passes through the central router.

**Figure 19.** (a) The network topology after the undesired changes. (b) The route from H8 to H5 now bypasses the cen‐ tral router.

This problem can be immediately repaired without major efforts: the administrator can set the central router to use RIPv2 broadcast version (for backwards compatibility), and the four floor routers to alternate between RIPv1 and RIPv2 multi-cast: the routers on an odd floor to RIPv1 and the routers on even floors to utilize RIPv2 multi-cast.

In the HypeRSimRIP application, this can be done by using the 'RIP version switch' window (Figure 20), accessible from the context menu of every device. Once all the new settings have been introduced, it can be observed (Figure 21) that even though the illegal routes are still active, they have been avoided.

This example has thus presented a practical use of two Internal Gateway Protocols (IGPs) inside the same network and the interaction between the three RIP switches. Moreover, the following statement: 'A network system with multiple incompatible IGPs can have a full routing table, if and only if the transitioning entities can translate the routing information' [16] has been proven true, and also been given an example: here the transitioning entity is the central router.

**Figure 20.** The RIP version switch window.

**Figure 18.** The route from H8 to H5 passes through the central router.

and the routers on even floors to utilize RIPv2 multi-cast.

active, they have been avoided.

tral router.

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central router.

**Figure 19.** (a) The network topology after the undesired changes. (b) The route from H8 to H5 now bypasses the cen‐

Proceedings of the International Conference on Interdisciplinary Studies (ICIS 2016) - Interdisciplinarity and Creativity

This problem can be immediately repaired without major efforts: the administrator can set the central router to use RIPv2 broadcast version (for backwards compatibility), and the four floor routers to alternate between RIPv1 and RIPv2 multi-cast: the routers on an odd floor to RIPv1

In the HypeRSimRIP application, this can be done by using the 'RIP version switch' window (Figure 20), accessible from the context menu of every device. Once all the new settings have been introduced, it can be observed (Figure 21) that even though the illegal routes are still

This example has thus presented a practical use of two Internal Gateway Protocols (IGPs) inside the same network and the interaction between the three RIP switches. Moreover, the following statement: 'A network system with multiple incompatible IGPs can have a full routing table, if and only if the transitioning entities can translate the routing information' [16] has been proven true, and also been given an example: here the transitioning entity is the

**Figure 21.** The route from H8 to H5 detours through the central router.
