Associating Track With Pbr - HP A5830 series Configuration Manual

If a static route needs route recursion, the associated track entry must monitor the next hop of the
recursive route instead of that of the static route. Otherwise, a valid route may be considered invalid.
For more information about static route configuration, see Layer 3

Associating track with PBR

PBR is a routing mechanism based on user-defined policies. Different from the traditional destination-
based routing mechanism, PBR enables you to use a policy (based on the source address and other
criteria) to route packets.
PBR cannot detect the availability of any action taken on packets. When an action is not available,
packets processed by the action may be discarded. For example, configure PBR to forward packets that
match certain criteria through a specific next hop. When the specified next hop fails, PBR cannot sense
the failure, and continues to forward matching packets to the next hop.
This problem can be solved by associating track with PBR, which improves the flexibility of PBR
application, and enables PBR to sense topology changes.
After you associate a track entry with an apply clause, the detection module associated with the track
entry sends the detection result of the availability of the object (an interface or an IP address) specified in
the apply clause.
The Positive state of the track entry shows that the object is available, and the apply clause is valid
•
The Negative state of the track entry shows that the object is not available, and the apply clause is
•
invalid
The Invalid state of the track entry shows that the apply clause is valid
•
The following objects can be associated with a track entry:
Next hop
•
Default next hop
•
Configuration prerequisites
Before you associate track with PBR, create a policy or a policy node and configure the match criteria as
well.
Configuration procedure
To associate track with PBR:
To do...
• Enter system view
• Create a policy or policy
node and enter PBR policy
node view
• Define an ACL match
criterion
• Set the next hop and
associate it with a track entry
Use the command...
system-view
policy-based-route policy-name [ deny |
permit ] node node-number
if-match acl acl-number
apply ip-address next-hop ip-address [
direct ] [ track track-entry-number ] [ ip-
address [ direct ] [ track track-entry-
number ] ]
166
IP Routing Configuration Guide.
—
Remarks
—
Required
Optional
By default, no packets are
filtered
Required
Configure at least one of
the commands