Perle Systems PERLE P850 - Manual (Page 57)

Applications
51
Configure Firewall
The P850 provides Firewall security for restricting access between any two
networks connected through the router. Firewalls are set up on a per
connection basis for the LAN and remote sites. The direction of filtering is
from the perspective of the P850; incoming traffic is from the network in
question to the P850, outgoing is from the P850 to the network. The
direction of filtering may be set to incoming, outgoing, both or none. Once
the direction of filtering for a connection has been set, holes may be created
in the firewall to allow specified traffic through. Normally, the LAN firewall
is used for restricting intranet traffic (connections within the corporate
network) and remote site firewalls are used to limit access from less trusted
sources, such as the Internet or dial-up links.
Figure 2-10 Sample Firewall Application
The above diagram shows a corporate head office network, which is
connected, to the Internet with an P850. There is also a branch office
at a remote site connected with a Digital Leased link. The
administrator at the corporate head office wishes to set up an IP
firewall to allow everyone on the Internet to have access to the
corporate FTP and Web servers and nothing else. The administrator
Internet
Router with
firewall enabled.
Corporate Head
Office Network
195.100.1.0
Branch Office
Network
195.100.2.0
Any other network
any IP address
Main FTP server: 195.100.1.12
Main Web server: 195.100.1.20