User Documentation

Version 1.2 / August 2020 Page 85 / 102
2. Configuring the packet filter (firewall) according to the above mentioned “Communica-
tion requirements”
Note: Since the Router is running in mode “Transparent bridge” we only need to configure new rules on tab
“Layer 2”.
2. 1 Configuration of a rule-set containing one rule to allow Modbus TCP (protocol TCP and port
502) traffic initiated from WAN port to LAN port.
►Go to menu Configuration → Packet filter.
►Select Tab “Layer 2”.
►Click ‘+’ icon to add a new rule set.
Figure 25: Factory default settings of Layer-2 Packet filter (firewall)
►Add a name for new rule-set (here Modbus_L2).
►Click ‘Next’.
►Select Inbound interface (here WAN) and outbound in-
terface (here LAN).
►Click Add to add a new rule inside of this rule-set named
Modbus_L2.
►Enter wild character * for source and destination MAC
addresses
►Select protocol IPv4 to be checked inside of the Ethernet
frame.
►Click ‘Next’.