ZyXEL Communications LTE7460-M608 User Manual page 81

Anti-Probing
If an outside user attempts to probe an unsupported port on your LTE7460-M608, an ICMP response
packet is automatically returned. This allows the outside user to know the LTE7460-M608 exists. The
LTE7460-M608 supports anti-probing, which prevents the ICMP response packet from being sent. This
keeps outsiders from discovering your LTE7460-M608 when unsupported ports are probed.
ICMP
Internet Control Message Protocol (ICMP) is a message control and error-reporting protocol between a
host server and a gateway to the Internet. ICMP uses Internet Protocol (IP) datagrams, but the messages
are processed by the TCP/IP software and directly apparent to the application user.
DoS Thresholds
For DoS attacks, the LTE7460-M608 uses thresholds to determine when to drop sessions that do not
become fully established. These thresholds apply globally to all sessions. You can use the default
threshold values, or you can change them to values more suitable to your security requirements.
7.17.2.1 Firewall Rules Overview
Your customized rules take precedence and override the LTE7460-M608's default settings. The LTE7460-
M608 checks the source IP address, destination IP address and IP protocol type of network traffic against
the firewall rules (in the order you list them). When the traffic matches a rule, the LTE7460-M608 takes the
action specified in the rule.
Firewall rules are grouped based on the direction of travel of packets to which they apply:
• LAN to Router
• LAN to WAN
By default, the LTE7460-M608's stateful packet inspection allows packets traveling in the following
directions:
• LAN to Router
These rules specify which computers on the LAN can manage the LTE7460-M608 (remote
management).
Note: You can also configure the remote management settings to allow only a specific
computer to manage the LTE7460-M608.
• LAN to WAN
These rules specify which computers on the LAN can access which computers or services on the
WAN.
By default, the LTE7460-M608's stateful packet inspection drops packets traveling in the following
directions:
• WAN to LAN
These rules specify which computers on the WAN can access which computers or services on the
LAN.
Chapter 7 Networking
• WAN to LAN
• WAN to Router
LTE7460-M608 User's Guide
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