ETHERLINE
®
ACCESS NF04T | Version 1 | 04/16/20
25
6.5
ICMP Traffic “WAN to LAN”
The Internet Control Message Protocol (ICMP) serves the purpose of exchanging information and error messages via
the Internet protocol IPv4. Typical ICMP frames include “ping” or “traceroute”.
With the “ICMP Traffic” option, you can generally allow the
directing of ICMP frames from the WAN to the LAN network
(“Accept”) or, depending upon the packet filters, prohibit this
(“Default Action”).
If, for example, the packet filters “Default Action” are set to
“Reject” or “Drop”, and ICMP Traffic to “Default Action”, then
no ICMP frames of any kind are allowed through.
6.6
Packet filter “LAN to WAN”
In the basic state, data traffic is permitted for devices from the machine network (LAN) to the production network
(WAN) without limitations (“Default Action”: “Accept”).
In the “LAN to WAN” packet filter, the communication of devices in LAN with devices in the production network
(WAN) or into the Internet is completely prohibited or is blocked or allowed for particular devices.
The entry of the filter rules corresponds to the packet filters “WAN to LAN”, except that the source IP is now the
LAN IP and the destination IP addresses a device in the WAN.
In the event that devices in the LAN should communicate with devices in the production network, “SNAT” should be
activated in “Basic NAT” settings.
A maximum of 128 packet filter rules per direction (“WAN to LAN” and “LAN to WAN”) can be defined.
