Packet Direction Examples - ZyXEL Communications ZYWALL 35 User Manual

Chapter 11 Firewall

11.3 Packet Direction Examples

Firewall rules are grouped based on the direction of travel of packets to which they apply. This
section gives some examples of why you might configure firewall rules for specific
connection directions.
By default, the ZyWALL allows packets traveling in the following directions.:
• LAN to LAN
• LAN to WAN
1
By default, the ZyWALL drops packets traveling in the following directions.
• WAN 1 to LAN These rules specify which computers connected to WAN 1 can access
• WAN to WAN
See Chapter 4 on page 109
246
These rules specify which computers on the LAN can manage the
ZyWALL (remote management) and communicate between networks or
subnets connected to the LAN interface (IP alias).
Note: You can also configure the remote management settings to
allow only a specific computer to manage the ZyWALL.
These rules specify which computers on the LAN can access which
computers or services connected to WAN 1. See
253 for an example.
which computers or services on the LAN. For example, you may
create rules to:
• Allow certain types of traffic, such as Lotus Notes database
synchronization, from specific hosts on the Internet to specific
hosts on the LAN.
• Allow public access to a Web server on your protected network.
You could also block certain IP addresses from accessing it.
Note: You also need to configure NAT port forwarding (or full
featured NAT address mapping rules) to allow computers
on the WAN to access devices on the LAN. See
21.5.3 on page 441
By default the ZyWALL stops computers connected to WAN1 or
WAN2 from managing the ZyWALL or using the ZyWALL as a
gateway to communicate with other computers on the WAN. You
could configure one of these rules to allow a WAN computer to
manage the ZyWALL.
Note: You also need to configure the remote management
settings to allow a WAN computer to manage the
ZyWALL.
for information about packets traveling to or from the VPN tunnels.
Section 11.5 on page
for an example.
ZyWALL 5/35/70 Series User's Guide
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