Lan To Wan Rules; Wan To Lan Rules; Figure 50 Lan To Wan Traffic - Nortel BSR252 Configuration - Basics

the LAN interface is an example of traffic destined for the Business Secure Router
LAN interface itself. You can also use LAN to LAN/Business Secure Router rules
with IP alias to control routing between two subnets on the LAN.
WAN to WAN/Business Secure Router rules apply to packets coming in through
the WAN interface that are destined for either the Business Secure Router WAN
interface itself or a different subnet on the WAN. A management session through
the WAN interface is an example of traffic destined for the Business Secure
Router WAN interface itself. By default, the Business Secure Router stops WAN
computers from using the Business Secure Router as a gateway to communicate
with other computers on the WAN. You can configure one of these rules to allow
a WAN computer to manage the Business Secure Router.

LAN to WAN rules

The default rule for LAN to WAN traffic is that all users on the LAN are allowed
unrestricted access to the WAN. When you configure a LAN to WAN rule, you in
essence want to limit some or all users from accessing certain services on the
WAN.

Figure 50 LAN to WAN traffic

WAN to LAN rules

The default rule for WAN to LAN traffic blocks all incoming connections (WAN
to LAN). If you want to allow certain WAN users to have access to your LAN,
you need to create custom rules to allow it.
Business Secure Router
Nortel Business Secure Router 252 Configuration — Basics
Chapter 11 Firewall screens 173