Ip Unicast Policy Routing Configuration; Introduction To Ip Unicast Policy Routing; Policy Routing; Track-Policy Routing Collaboration - H3C S9500E Series Configuration Manual

IP unicast policy routing configuration

Introduction to IP unicast policy routing

Policy routing

IP unicast policy routing is used to route IP unicasts based on a policy. Policy routing, also known
as PBR, is a routing mechanism based on user-defined policies. Different from the traditional
destination-based routing mechanism, policy routing enables you to use a policy based on the
source address, and other criteria, to route packets.
According to the objects to which the policy routing applies, policy routing involves local policy
routing and interface policy routing.
•
Local policy routing applies to locally generated packets only, such as the ICMP packets
generated by using the ping command.
•
Interface policy routing applies to packets forwarded through the interface only.
In most cases, interface policy routing is implemented to meet the forwarding and security
requirements.
Policy routing takes precedence over destination-based routing. That is, policy routing is applied
to the packets matching the specified criteria, and other packets are forwarded through
destination-based routing.

Track-policy routing collaboration

Associated with a track object, IP unicast policy routing can detect topology changes faster. You
can associate the policy routing with a track entry when configuring the default next hop of
packets, and use the detection modules to monitor the reachability of the link where the next hop
of the packets resides, so as to dynamically determine the availability of the policy.
•
If the status of the track entry is positive or invalid, then the link is reachable, the operation
of setting the next hop takes effect, and the configuration can be used to instruct forwarding.
•
If the status of the track entry is negative, then the link is unreachable, the operation of
setting the next hop does not take effect, and the configuration is ignored during packet
forwarding.
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