HP 6125XLG R2306-HP 6125XLG Blade Switch Layer 3 - IP Routing Configuration Gu - Page 349

Configuring IPv6 PBR, Introduction to IPv6 PBR, Policy, if-match clause, apply clause

Page 349 highlights

Configuring IPv6 PBR Introduction to IPv6 PBR Policy-based routing (PBR) uses user-defined policies to route packets. A policy can specify the next hop and other parameters for packets that match specific criteria such as ACLs. A device uses PBR to forward matching packets and uses the routing table to forward non-matching packets. If PBR is not configured, the device uses the routing table to forward packets. The device supports only interface PBR, which 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 comprises 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 matches nodes in priority order against packets. If a packet satisfies the match 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 only the if-match acl clause, which sets an ACL match criterion. You can specify only one if-match clause of each type for a node. apply clause IPv6 PBR supports only the apply next-hop clause, which sets the next hop for packets. Relationship between the match mode and clauses on the node Does a packet match all the if-match clauses on the node? Yes No Match mode In permit mode In deny mode • If the node is configured with an apply clause, IPv6 PBR executes the apply clause on the node. • If the node is configured with no The packet is forwarded according to the routing table. apply clause, the packet is forwarded according to the routing table. IPv6 PBR matches the packet against IPv6 PBR matches the packet against the next node. the next node. 338

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338
Configuring IPv6 PBR
Introduction to IPv6 PBR
Policy-based routing (PBR) uses user-defined policies to route packets. A policy can specify the next hop
and other parameters for packets that match specific criteria such as ACLs.
A device uses PBR to forward matching packets and uses the routing table to forward non-matching
packets. If PBR is not configured, the device uses the routing table to forward packets.
The device supports only interface PBR, which 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 comprises
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 matches nodes in priority order against packets. If a packet satisfies the match 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 only the
if-match acl
clause, which sets an ACL match criterion.
You can specify only one
if-match
clause of each type for a node.
apply clause
IPv6 PBR supports only the
apply next-hop
clause, which sets the next hop for packets.
Relationship between the match mode and clauses on the node
Does a packet match all the
if-match clauses on the
node?
Match mode
In permit mode
In deny mode
Yes
If the node is configured with an
apply
clause, IPv6 PBR executes
the
apply
clause on the node.
If the node is configured with no
apply
clause, the packet is
forwarded according to the
routing table.
The packet is forwarded according
to the routing table.
No
IPv6 PBR matches the packet against
the next node.
IPv6 PBR matches the packet against
the next node.