Dependencies Between Configuration Items; Null Value Representations - Cisco CRS-1 - Carrier Routing System Router Api Manual

Chapter 4 Cisco CRS-1 Series XML and Native Data Operations
</BGP>
</Operational>
Leaf Nodes
The leaf nodes hold values and are generally simple one-value items where the element representing the
leaf node uses character data to specify the value (as in "<DefaultMetric>10</DefaultMetric>" in the
example in the section
specify—for example, when you configure the administrative distance for an address family (the
<Distance> element), three values must be given together. Specifying more than one value is achieved
by adding further child elements to the leaf, each of which indicates the particular value being
configured.
The following example shows leaf nodes:
<Configuration>
<BGP>
</BGP>
</Configuration>
Sometimes there may be even more structure to the values (with additional levels in the hierarchy
beneath the <Distance> tag as a means for grouping the related parts of the data together), although they
are still only "setable" or "getable" as one entity. The extreme example of this is that in some of the
information returned from the operational data model, all of the values pertaining to the status of a
particular object may be grouped as one leaf. For example, a request to retrieve a particular BGP path's
status will return all the values associated with that path.

Dependencies Between Configuration Items

Dependencies between configuration items are not articulated in the XML schema nor are they enforced
by the XML infrastructure; for example, if item A is this value, then item B must be one of these values,
and so forth. The back-end Cisco CRS-1 Series operating system applications are responsible for
preventing inconsistent configuration from being set. In addition, the management agents are responsible
for carrying out the appropriate operations on dependent configuration items through the XML interface.

Null Value Representations

The standard attribute "xsi:nil" is used with a value of "true" when a null value is specified for an
element in an XML request or response document.
The following example shows how to specify a null value for the element <HoldTime>:
OL-4596-01
<AF>IPv4Unicast</AF>
</BGP_AFFilter>
</Filter>
</NeighborTable>
"Main Hierarchy
.
.
.
<Distance>
<ExternalRoutes>20</ExternalRoutes>
<InternalRoutes>250</InternalRoutes>
<LocalRoutes>200</LocalRoutes>
</Distance>
.
.
.
Structure". In some cases there may be more than one value to
Cisco CRS-1 Series Carrier Routing System XML API Guide
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