Filter Policies
Router Configuration Guide 485
Primary and Secondary Filter Policy Action for PBF Redundancy
In some deployments, operators may want to specify a backup Policy-Based Forwarding
(PBF) target if the primary target is down. The SR OS allows the configuration of a primary
action (config>filter>{ip-filter | ipv6-filter | mac-filter}>entry>action) and a secondary
action (config>filter>{ip-filter | ipv6-filter | mac-filter}>entry>action secondary) as part
of a single filter policy entry. The secondary action can only be configured if the primary
action is configured.
For L2 PBF redundancy, the operator can configure the following redundancy options:
• action forward sap AND action secondary forward sap
• action forward sdp AND action secondary forward sdp
• action forward sap AND action secondary forward sdp
• action forward sdp AND action secondary forward sap
When primary and secondary actions are configured, PBF uses the primary action if the
primary target is operationally up or secondary action if the primary PBF target is
operationally down. If both targets are down, the default filter entry behavior on PBF target
down as per the primary action configuration is used, unless pbr-down-action-override is
configured.
When PBF redundancy is configured, the operator can use sticky destination functionality for
a given redundant filter entry. When sticky destination is configured (config>filter>{ip-filter
| ipv6-filter | mac-filter}>entry>sticky-dest), the functionality mimics that of sticky
destination configured for redirect policies. To force a switchover from the secondary to
primary action when sticky destination is enabled and secondary action is selected, the
operator can use the tools>perform>filter>{ip-filter | ipv6-filter | mac-
filter}>entry>activate-primary-action command.
The show>filter>{ip-filter | ipv6-filter | mac-filter} [entry] command displays which
redundant action is activated or downloaded, including when both PBF targets are down. The
following example shows partial display of the command as applicable for PBF redundancy.
*A:vsim-200001# show filter ip 10 entry 1000
…
Primary Action : Forward (SAP) <-details of (primary) action
Next Hop : 1/1/1
Service Id : Not configured
PBR Target Status : Does not exist
Secondary Action : Forward (SAP) <-details of secondary action
Next Hop : 1/1/2
Service Id : Not configured
PBR Target Status : Does not exist
PBR Down Action : Forward (pbr-down-action-override) <- PBR down behavior
Downloaded Action : None <- currently downloaded action
Dest. Stickiness : 1000 Hold Remain : 0 <- sticky dest details
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