Series Machines With Netmap And Destination Nat - Siemens SCALANCE S615 Manual

2 UseCases at a Glance
2.5

Series machines with NETMAP and destination NAT

Starting situation
In this case, several identical plant parts are to be accessed by a PC.
Consequently, all plant parts use the same subnet (in this document: 192.168.2.x).
Without a gateway, the PC is to communicate with each CPU from the plant parts
and execute any functions.
SRC IP:
192.168.1.10
DST IP:
192.168.1.2
SRC IP:
192.168.1.10
DST IP:
192.168.2.10
Requirement
A SCALANCE S615 is connected upstream to each plant part.
For network separation, the SCALANCE S615 has two VLANs with different
network IDs. As a result, the device has a separate IP address for each VLAN
(in this document: VLAN1: 192.168.2.1 and VLAN2: 192.168.1.1 or 192.168.1.5).
The SCALANCE S615 modules and the PC are connected via VLAN2.
This configuration requires NAT and cannot be solved with pure routing as the
subnet from VLAN1 could not be uniquely assigned, regardless of the direction of
connection establishment and gateways in the PC.
One SCALANCE S615 module is required for each identical internal subnet. It is
not possible to connect multiple identical subnets to a single SCALANCE S615.
Therefore, a NAT table is additionally defined in the SCALANCE S615 to translate
the PC's message frames to a different IP address. This requires another IP
address from the subnet of VLAN2.
NAT_S615
Entry ID: 109744660, V1.1,
VLAN2: 192.168.1.0/24
192.168.1.1
Addtl. IP:
192.168.1.2
Addtl. IP:
192.168.1.3
192.168.2.1
CPU: 192.168.2.10 CPU: 192.168.2.10
Gateway: 192.168.2.1 Gateway: 192.168.2.1
VLAN1: 192.168.2.0/24
08/2017
PC:
192.168.1.10
Gateway:
None
SRC IP:
192.168.1.10
DST IP:
192.168.1.5
192.168.1.3
SRC IP:
192.168.1.10
DST IP:
192.168.2.1
192.168.2.10
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