Overview Of Portmaster Filtering - Lucent Technologies PortMaster 4 Configuration Manual

This chapter describes how to configure input and output packet filters. IP, IPX, and
Service Advertising Protocol (SAP) rules are reviewed, and filter examples are given.
You can also use the ChoiceNet application to filter IP packets by lists of sites rather than
by individual IP addresses. For more information on ChoiceNet, see the ChoiceNet
Administrator's Guide.
This chapter discusses the following topics:
• "Overview of PortMaster Filtering" on page 8-1
• "Creating Filters" on page 8-4
• "Displaying Filters" on page 8-7
• "Deleting Filters" on page 8-7
• "Example Filters" on page 8-7
• "Restricting User Access" on page 8-12
Each topic in this chapter includes examples of filters used to accomplish the goal
described.
See the PortMaster 4 Command Line Reference for more detailed command descriptions and
instructions.
You can also configure the PortMaster 4 using the PMVision application for Microsoft
Windows, UNIX, and other platforms supporting the Java Virtual Machine (JVM).
PMVision replaces the PMconsole interface to ComOS.
The FilterEditor application provides a graphical interface to construct and edit filters for
both PortMaster 4 Remote Access Concentrators and ChoiceNet servers.
PMVision, FilterEditor, and other Java-based configuration tools for the PortMaster are
available via anonymous FTP at
ftp://ftp.livingston.com/pub/livingston/software/java/.

Overview of PortMaster Filtering

Packet filters can increase security and decrease traffic on your network. You use filters
to limit certain kinds of internetwork communications by permitting or denying the
passage of packets through network interfaces. By creating appropriate filters, you can
control access to specific hosts, networks, and network services.
You can enhance security on your network by limiting authorized activities to certain
hosts. For example, you can restrict the DNS and SMTP interchange with the Internet to
a well-secured host on your network. All Internet hosts can then access only this single
server for those services. If you have several name servers or mail servers, you can use
additional rules to allow access to these servers.
Configuring Filters 8
8-1