Specifications
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• Figure 66: Classless Arctic LAN
As we look closer to Arctic’s LAN, we can see that the IP addresses are from class A private
network, but the netmask, 255.255.255.248 is not. The class A has been subnetted to smaller
networks having 8 IP addresses per network.
The number of IP addresses in class A private network is 16777216. It would be a waste of IP
addresses to use all 16777216 addresses, when there is only a need for 8 IP addresses.
Instead, by dividing the class A private IP address space to networks having 8 IP addresses,
there is now a possibility in theory to have 2097152 Arctic’s, each having 8 IP address
network, which can handle 6 TCP/IP connected devices, Arctic included (2 IP addresses are
consumed for network and broadcast address per network). See Table 9: Classless LAN of
Arctic for reference.
IP address Netmask Description
10.10.10.0 255.255.255.248 Network address
10.10.10.1 255.255.255.248 Arctic
10.10.10.2 255.255.255.248 Device #1
10.10.10.3 255.255.255.248 Device #2
10.10.10.4 255.255.255.248 Reserved for future
10.10.10.5 255.255.255.248 Reserved for future
10.10.10.6 255.255.255.248 Reserved for future
10.10.10.7 255.255.255.248 Broadcast address
• Table 9: Classless LAN of Arctic
17.6. Routing
A typical scenario of routing in Viola Systems M2M solution is that there is a network behind the
M2M GW and a network behind the Arctic. Furthermore, the devices connected to these two
networks may need to communicate with each others. An example of such communication would
be a SCADA system in the LAN of M2M GW that communicates with an Ethernet device,
connected to Arctic's LAN at remote site.
In routing point of view, the M2M GW knows a route to each Arctic via the VPN peer IP addresses.
For achieving an end-to-end communication between two devices residing at LANs of M2M GW
and Arctic, this is not enough; it is needed to tunnel the local area networks over the VPN
connection.
This is done in the M2M GW and Arctic by setting the VPN parameter “Tunnel the following
network” with the required value of the network IP address of the opposite end's LAN
.