User manual

Product Description
33002479 06 07/2008 59
Security
Overview The following information describes firewalls. A firewall is a gateway that controls
access to your network. To restrict access to your Ethernet controller and I/O
network, you may want to consider a firewall.
Types of
Firewalls
There are network-level and application-level firewalls:
z Network-level firewalls: These firewalls are frequently installed between the
Internet and a single point of entry to an internal, protected network.
z Application-level firewalls: An application-level firewall acts on behalf of an
application. It intercepts all traffic destined for that application and decides
whether to forward that traffic to the application. Application-level firewalls reside
on individual host computers
Port Numbers
Used by NOE
The following table contains the port numbers used by NOE:
You may need to provide the information in this table to your system administrator
so that the firewall configuration will allow access to your PLC from outside of your
facility.
Protocol Port Number
Modbus/TCP TCP 502
HTTP TCP 80
SNMP UDP 61
FTP TCP 21