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DES-7200 Configuration Guide Chapter 7 Policy-based Routing
Configuration
7-5
specify the policy on packet forwarding. The route map consists of a set of
statements with permit or deny action.
Secondly, define a set of set statements in the route map to forward and control
packets in order.
Finally, apply the policy-based routing at the inbounding direction. If the
policy-based routing is applied at the outbounding direction, packets are
forwarded by common routes.
For routers, outgoing packets can be processed by the specific policy-based
routing, not the common routing table.
7.2 Default Configurations
Below describes the default configurations of policy-based routing.
Function Default value
Load balance of many next hops Redundancy (redundant backup)
Next hop WCMP weight 1
7.3 Configure IPv4 Policy-based Routing
You need to set a route map for the policy-based routing and create the route
map before applying the policy-based routing. A route map consists of many
policies with corresponding sequences. The smaller the sequence, the higher the
policy is. Each policy consists of one or more match statements and
corresponding one or more set statements. The match statement defines the
matching rule of IPv4/v6 packets, and the set statement defines the processing
rules of matched IPv4/v6 packets. In the course of policy-based routing, packets
are matched by priorities in descending order. Once a policy is matched, the
system performs corresponding actions and quits policy-based routing.
There is one kind of match statement. match ip address matches packets by
ACL. For a policy, you can configure many match ip address statements.
Similarly, there are two types of set statements. Type 1 modifies the QoS field of
IP packet, for instance, set ip tos, set ip precedence and set ip dscp. Type 2
controls IP packet, for instance, set vrf, set ip nexthop and set ip default
nexthop. Once all match rules are met, Type 1 set statements must be executed
and Type 2 set statements are executed by priority in the following order:
set vrf: Set policy-based routing as the VRF instance for IP packet routing with
the priority higher than common route. The command is mutually exclusive with
set ip [default] nexthop. The IPv4 packets received on the interface that meet
match rules will be routed by the routing table of the VRF instance specified by