Nortel BSR222, Configuration, Page: 170 / 451

170 Chapter 10 Firewalls
NN47922-500
• The firewall uses session filtering, or smart rules, that enhance the filtering
process and control the network session rather than control individual packets
in a session.
• The firewall provides e-mail service to notify you of routine reports and when
alerts occur.
When to use the firewall
1 To prevent DoS attacks and prevent hackers cracking your network.
2 A range of source and destination IP addresses as well as port numbers can be
specified within one firewall rule, making the firewall a better choice when
complex rules are required.
3 To selectively block or allow inbound or outbound traffic between inside host
or networks and outside host or networks. Remember that filters cannot
distinguish traffic originating from an inside host or an outside host by IP
address.
4 The firewall performs better than filtering if you need to check many rules.
5
Use the firewall if you need routine e-mail reports about your system or need
to be alerted when attacks occur.
6
The firewall can block any specific URL traffic that occurs in the future. The
URL can be saved in an Access Control List (ACL) database.