ZyXEL Communications ZyWALL 10, Руководство пользователя

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ZyWALL 10 Internet Security Gateway
Example Firewall Rules 19-1
Chapter 19
Example Firewall Rules
19.1 Examples
Please note that whenever you open a hole in the firewall to forward a service from the Internet to the local
network, and NAT is also enabled, you may have to also configure a server behind NAT using SMT menu
15.2. Please see the chapter on NAT for more detailed information on NAT and also
see Figure 14-5 for a
view of how Filtering, the Firewall and NAT interact.
19.1.1 Example 1 - Firewall Rule To Allow Web Service From The Internet
Let’s say you have one server on the local network, with an IP of 10.100.1.2, supporting FTP, HTTP,
Telnet and mail services. The only traffic allowed from the Internet is web service. You want to be able to
forward all traffic initiated from the local network. You want to know who accesses your server and send e-
mail alerts when this happens. Assume, for example, your mail account is
user@zyxel.com . Another
network administrator has an e-mail address of user2@zyxel.com . Follow the steps below.
Step 1.
Activate the firewall. You may activate the firewall by ZyWALL Web Configurator shown next
(click
Configuration , the Config tab, then check the Firewall Enabled box) or in SMT Menu
21.2. You can only configure the firewall using the ZyWALL Web Configurator or CI
commands (
see the Appendix ). When the firewall is active, the default rules allow all traffic
from the local network to the WAN (Internet) and block all traffic from the Internet to the local
network.