Sample XPath Notifications Received on Devices for a Modified E-LAN Service
While developing configlets, XPaths and Regular Expressions would be used intensively. It would be desirable to let the user define frequently used XPaths and Regular expressions in such a way that they can be referred when required. User can define these templates from the Xpath and Regex task group in the CLI Configlets workspace of the Junos Space Platform GUI. For an E-LAN service that is modified using the Connectivity Services Director application, the XPath attributes corresponding to the modified configuration settings and parameters are sent to the associated devices of the service for the revised configuration elements to be applied on the devices. 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 modified E-LAN service:
The following is the changed XPath attribute for a routing instance of a modified E-LAN service:
/configuration/routing-instances/instance/route-distinguisher/rd-type
The following is the differential configuration set for the XPath attribute for a routing instance of a modified E-LAN service:
<?xml version="1.0" encoding="UTF-8"?>
<rpc-reply op="U">
<configuration op="U">
<routing-instances op="U">
<instance op="U">
<name>VplsBasicSO</name>
<instance-type>vpls</instance-type>
<interface>
<name>ge-0/1/4.69</name>
</interface>
<route-distinguisher op="U">
<rd-type op="U">36001:7</rd-type>
</route-distinguisher>
<vrf-target>
<community>target:36000:6</community>
</vrf-target>
<protocols>
<vpls>
<mac-table-size>
<limit>5120</limit>
</mac-table-size>
<interface-mac-limit>
<limit>1024</limit>
</interface-mac-limit>
<no-tunnel-services/>
<site>
<name>Site_1</name>
<site-identifier>1</site-identifier>
<site-preference>primary</site-preference>
<interface>
<name>ge-0/1/4.69</name>
</interface>
</site>
</vpls>
</protocols>
</instance>
</routing-instances>
</configuration>
</rpc-reply>
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
The following is the configuration difference for the XPath attribute of physical interfaces:
<?xml version="1.0" encoding="UTF-8"?>
<rpc-reply op="U">
<configuration op="U">
<system>
<services/>
</system>
<chassis/>
<interfaces op="U">
<interface op="U">
<name>ge-0/0/5</name>
<flexible-vlan-tagging/>
<mtu op="U">1520</mtu>
<encapsulation>flexible-ethernet-services</encapsulation>
<unit>
<name>29</name>
<encapsulation>vlan-vpls</encapsulation>
<vlan-tags>
<outer>34</outer>
</vlan-tags>
<family>
<vpls>
<filter>
<input>
<filter-name>filter_in_ge-0/0/5_29</filter-name>
</input>
</filter>
</vpls>
</family>
</unit>
</interface>
</interfaces>
</configuration>
</rpc-reply>
The following is the changed XPath attribute for the logical unit of an interface:
/configuration/interfaces/interface/unit/vlan-tags/outer
The following is the configuration difference for the XPath attribute of logical unit of an interface:
<?xml version="1.0" encoding="UTF-8"?>
<rpc-reply op="U">
<configuration op="U">
<system>
<services/>
</system>
<chassis/>
<interfaces op="U">
<interface op="U">
<name>ge-0/0/5</name>
<flexible-vlan-tagging/>
<mtu>1522</mtu>
<encapsulation>flexible-ethernet-services</encapsulation>
<unit op="U">
<name>29</name>
<encapsulation>vlan-vpls</encapsulation>
<vlan-tags op="U">
<outer op="U">34</outer>
</vlan-tags>
<family>
<vpls>
<filter>
<input>
<filter-name>filter_in_ge-0/0/5_29</filter-name>
</input>
</filter>
</vpls>
</family>
</unit>
</interface>
</interfaces>
</configuration>
</rpc-reply>
The following are the changed XPath attributes for a firewall
filter at the [edit firewall family vpls] hierarchy level:
/configuration/firewall/family/vpls/filter/term/then/discard,
/configuration/firewall/family/vpls/filter/term/name
The following is the configuration difference for the XPath attribute of a firewall filter in an E-LAN family:
<?xml version="1.0" encoding="UTF-8"?>
<rpc-reply op="U">
<configuration op="U">
<system>
<services/>
</system>
<chassis/>
<interfaces op="U">
<interface op="U">
<name>ge-0/0/5</name>
<flexible-vlan-tagging/>
<mtu op="U">1520</mtu>
<encapsulation>flexible-ethernet-services</encapsulation>
<unit>
<name>29</name>
<encapsulation>vlan-vpls</encapsulation>
<vlan-tags>
<outer>34</outer>
</vlan-tags>
<family>
<vpls>
<filter>
<input>
<filter-name>filter_in_ge-0/0/5_29</filter-name>
</input>
</filter>
</vpls>
</family>
</unit>
</interface>
</interfaces>
</configuration>
</rpc-reply>
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 is the configuration difference for the XPath attribute of a firewall policer:
<?xml version="1.0" encoding="UTF-8"?>
<rpc-reply op="U">
<configuration op="U">
<system>
<services/>
</system>
<chassis/>
<interfaces op="U">
<interface op="U">
<name>ge-0/0/5</name>
<flexible-vlan-tagging/>
<mtu op="U">1520</mtu>
<encapsulation>flexible-ethernet-services</encapsulation>
<unit>
<name>29</name>
<encapsulation>vlan-vpls</encapsulation>
<vlan-tags>
<outer>34</outer>
</vlan-tags>
<family>
<vpls>
<filter>
<input>
<filter-name>filter_in_ge-0/0/5_29</filter-name>
</input>
</filter>
</vpls>
</family>
</unit>
</interface>
</interfaces>
</configuration>
</rpc-reply>
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.