Configuring Ipv6 Pbr; Overview; Policy - HP HPE FlexNetwork 7500 series Configuration Manual

Configuring IPv6 PBR

Overview

Policy-based routing (PBR) uses user-defined policies to route packets. A policy can specify the next
hop for packets that match specific criteria such as ACLs.
A device forwards received packets using the following process:
1. The device uses PBR to forward matching packets.
2. If the packets do not match the PBR policy or the PBR-based forwarding fails, the device uses
the routing table, excluding the default route, to forward the packets.
3. If the routing table-based forwarding fails, the device uses the default route to forward packets.
PBR includes local PBR and interface PBR.
•
Local PBR guides the forwarding of locally generated packets, such as the ICMP packets
generated by using the ping command.
•
Interface PBR guides the forwarding of packets received on an interface only.

Policy

An IPv6 policy includes match criteria and actions to be taken on the matching packets. A policy can
have one or multiple nodes as follows:
•
Each node is identified by a node number. A smaller node number has a higher priority.
•
A node contains if-match and apply clauses. An if-match clause specifies a match criterion,
and an apply clause specifies an action.
•
A node has a match mode of permit or deny.
An IPv6 policy compares packets with nodes in priority order. If a packet matches the criteria on a
node, it is processed by the action on the node. Otherwise, it goes to the next node for a match. If the
packet does not match the criteria on any node, it is forwarded according to the routing table.
if-match clause
IPv6 PBR supports the if-match acl clause, which sets an ACL match criterion.
You can specify only one if-match clause for each node.
apply clause
IPv6 PBR supports the types of apply clauses shown in
clauses for a node, but some of them might not be executed. The following apply clauses determine
the packet forwarding paths in a descending order:
•
apply next-hop
•
apply output-interface
Table 30 Priorities and meanings of apply clauses
Clause
apply precedence
apply next-hop and apply
output-interface
Meaning
Sets an IP precedence.
Sets next hops and sets output
interfaces.
494
Table 30. You can specify multiple apply
Priority
This clause is always executed.
Only the apply next-hop clause
is executed when both are
configured.