Manageable ethernet switches should have following approvals. 

 UL – 508 and 1604 

 CSA – 22.2 No. 142 

 CE Mark per EN61131-2 

 FM Class 1, Div 2 

 UL1604 Class 1 Div2 

 C-Tick for Australia 

 Substation IEC 61850 EMC levels tested 

 Maritime approval (GL) 

## 8.20 Network Firewall (firewall) 

## 8.20.1 General 

Firewall is a tool which controls data which is received from internet and prevents or allows passage according to your firewall configuration. 

## 8.20.2 Properties of Industrial Firewall 

 Firewall will maintain copper cable and fiber ethernet connection. 

 Firewall will be switch in layer 2 mode and will be router in layer 3 mode or it will be able to operated as PPPoE Point to Point Protocol Over Ethernet 

 Firewall will be equipped with firewall access controls 

 Package filtering for creating firewall rules: 

o SNMP v1/v2/v3 password 

o SSH (Secure shell protocol) input 

o External identity 

o IP packages incoming from device which is connected to external connection point. 

 NAT (Network Address Translation): 

 Network security capacity 

o IP packages which are delivered to internal connection point 

o Incoming MAC packages 

o Outgoing MAC packages 

o P Masquerading 

o 1:1 NAT (network address translation) 

o Port routing 

o IP Masquerading 

o 1:1 NAT (Network address translation 

