NETGEAR UTM5EW-100NAS Appliance Reference Manual page 121

Whether or not DHCP is enabled, how the PCs accesses the server's LAN address impacts the
inbound rules. For example:
• If your external IP address is assigned dynamically by your ISP (DHCP enabled), the IP
address might change periodically as the DHCP lease expires. Consider using Dyamic DNS so
that external users can always find your network (see
page 3-19).
• If the IP address of the local server PC is assigned by DHCP, it might change when the PC is
rebooted. To avoid this, use the Reserved (DHCP Client) feature in the LAN Groups menu to
keep the PC's IP address constant (see
• Local PCs must access the local server using the PCs' local LAN address. Attempts by local
PCs to access the server using the external WAN IP address will fail.
Note: See "Configuring Port Triggering" on page 5-46
certain types of inbound traffic that would otherwise be blocked by the firewall.
Note: The UTM always blocks denial of service (DoS) attacks. A DoS attack does not
attempt to steal data or damage your PCs, but overloads your Internet connection
so you cannot use it (that is, the service becomes unavailable). For example,
multiple concurrent connections of the same application from one host or IP
addresses (such as multiple DNS queries from one PC) triggers the UTM's DoS
protection. For more information about protecting the UTM from incoming
threats, see
Table 5-3 on page 5-8
common to most Inbound Service screens (see
and Figure 5-10 on page
The steps to configure inbound rules are described in the following sections:
• "Setting LAN WAN Rules" on page 5-12
• "Setting DMZ WAN Rules" on page 5-15
• "Setting LAN DMZ Rules" on page 5-19
Firewall Protection
ProSecure Unified Threat Management (UTM) Appliance Reference Manual
"Setting Up Address Reservation" on page
"Using the Intrusion Prevention System" on page
describes the fields that define the rules for inbound traffic and that are
5-21).
v1.0, January 2010
"Configuring Dynamic DNS" on
for yet another way to allow
Figure 5-4 on page 5-15,
4-17).
5-49.
Figure 5-7 on page 5-18
5-7