HP HPE FlexNetwork 7500 series, Configuration Manual

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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 Table 30 . You can specify multiple apply
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 Meaning Priority
apply precedence Sets an IP precedence. This clause is always executed.
apply next-hop and apply
output-interface
Sets next hops and sets output
interfaces.
Only the apply next-hop clause
is executed when both are
configured.