loopback_cfg.xml

<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0" xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0">
  <native xmlns="http://cisco.com/ns/yang/Cisco-IOS-XE-native">
    <interface>
      <Loopback>
        <name>99</name>
      </Loopback>
    </interface>
  </native>
  <interfaces xmlns="http://openconfig.net/yang/interfaces">
    <interface>
      <name>Loopback99</name>
      <config>
        <name>Loopback99</name>
        <type xmlns:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">ianaift:softwareLoopback</type>
        <enabled>true</enabled>
      </config>
      <subinterfaces>
        <subinterface>
          <index>0</index>
          <config>
            <index>0</index>
            <enabled>true</enabled>
          </config>
          <ipv6 xmlns="http://openconfig.net/yang/interfaces/ip">
            <config>
              <enabled>false</enabled>
            </config>
          </ipv6>
        </subinterface>
      </subinterfaces>
    </interface>
  </interfaces>
  <interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces">
    <interface>
      <name>Loopback99</name>
      <type xmlns:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">ianaift:softwareLoopback</type>
      <enabled>true</enabled>
      <ipv4 xmlns="urn:ietf:params:xml:ns:yang:ietf-ip"/>
      <ipv6 xmlns="urn:ietf:params:xml:ns:yang:ietf-ip"/>
    </interface>
  </interfaces>
</config>