Sample XPath Notifications Received on Devices for a Created E-Line Service
This topic illustrates the differential configuration, which is the delta or the change-set of the configuration that you are about to deploy on the devices, and the XPath attributes associated with the delta configuration for a newly created E-Line service. The following two scenarios need to be handled for E-Line services. Accordingly, the mechanism to identify impacted services is implemented.
A or Z endpoint of the existing service
A pseudowire extension for E-LAN or E-LAN services
The following is the changed XPath attribute for Layer 2 circuit of a newly created E-Line service:
/configuration/protocols/l2circuit/neighbor/interface/description
The following is the configuration difference corresponding to the XPath attribute for Layer 2 circuit:
<protocols op="U">
<l2circuit op="U">
<neighbor op="U">
<name>128.220.3.158</name>
<interface>
<name>ge-0/1/5.560</name>
<virtual-circuit-id>1</virtual-circuit-id>
<mtu>1522</mtu>
</interface>
<interface>
<name>ge-0/1/5.512</name>
<virtual-circuit-id>2</virtual-circuit-id>
<mtu>1522</mtu>
</interface>
<interface op="U">
<name>ge-0/0/3.0</name>
<virtual-circuit-id>221</virtual-circuit-id>
<description op="U">TestP2P2</description>
<community>R2-to-R1</community>
<mtu>1522</mtu>
</interface>
</neighbor>
</l2circuit>
</protocols>
For the policy- statement statement at the [edit policy-options] hierarchy level, the correct XPath Notification is not received if changes happen only to the policy-statement. The notification does not contain the changed XPath and configuration difference. Therefore, it is not possible to determine the instance of service impacted due to the change (when only localized to policy-options->policy-statement). Full service recovery is recommended in such cases.
The following is the changed XPath attribute for physical interfaces:
/configuration/interfaces/interface/mtu
The following is the changed XPath attribute for the logical unit of interfaces:
/configuration/interfaces/interface/unit/description
The following are the changed XPath attributes for the policer statement at the [edit firewall] hierarchy level:
/configuration/firewall/policer/if-exceeding/bandwidth-percent /configuration/firewall/policer/if-exceeding/bandwidth-limit
The following are the changed XPath attributes for the filter statement at the [edit firewall family family-name filter filter-name term term-name] hierarchy level
/configuration/firewall/filter
The service instance cannot be determined if the changes to policer occur and in such cases ,you need to determine the type of service and also identify whether the change is to existing service or a new service. You can select a service instance and the operation type (such as create or modify) to recover service for that endpoint. Using changed XPath and applying the differential configuration to the changed XPath, you can determine the type of change and the name of the changed configuration parameter.