Chapter 17 Policy, Firewall Filter, And Class-Of-Service Overview; Routing Policy Overview; Routing Policy Components - Juniper J2300 User Manual

Term
rule
service set
stateful firewall filter
stateless firewall filter
term
trusted network
untrusted network

Routing Policy Overview

Routing protocols send information about routes to a router's neighbors. This
information is processed and used to create routing tables, which are then distilled
into forwarding tables. Routing policies control the flow of information between the
routing protocols and the routing tables and between the routing tables and the
forwarding tables. Using policies, you can determine which routes are advertised,
specify which routes are imported into the routing table, and modify routes to
control which routes are added to the forwarding table.
This section contains the following topics:

Routing Policy Components

Routing policies are made up of one or more terms, which contain a set of
match conditions and a set of actions. Match conditions are criteria that a route
must match before the actions can be applied. If a route matches all criteria,
one or more actions are applied to the route. These actions specify whether to
accept or reject the route, control how a series of policies are evaluated, and
manipulate the characteristics associated with a route.
Definition
Guide that the Services Router follows when applying services. A rule consists of a match
direction and one or more terms.
Collection of services. Examples of services include stateful firewall filters and network address
translation (NAT).
Type of firewall filter that evaluates the context of connections, permits or denies traffic based
on the context, and updates this information dynamically. Context includes IP source and
destination addresses, TCP port numbers, TCP sequencing information, and TCP connection
flags.
Type of firewall filter that statically evaluates the contents of packets transiting the router, and
packets originating from, or destined for, the router. Information about connection states is
not maintained.
Firewall filters contain one or more terms that specify filter match conditions and actions.
Network from which all originating traffic can be trusted—for example, an internal enterprise
LAN. Stateful firewall filters allow traffic to flow from trusted to untrusted networks.
Network from which all originating traffic cannot be trusted—for example, a WAN. Unless
configured otherwise, stateful firewall filters do not allow traffic to flow from untrusted to
trusted networks.
Routing Policy Components on page 353
Applying Routing Policies on page 358
Policy, Firewall Filter, and Class-of-Service Overview
Routing Policy Overview
353