loopbacks:
  loop0:
    description: "Loopback, no config"
  loop1:
    description: "Loopback, both LCP and address"
    mtu: 2000
    lcp: "loop56789012345"
    addresses: [ 192.0.2.1/29, 2001:db8::1/64 ]
  loop2:
    description: "Loopback, invalid because it has an address but no LCP"
    mtu: 2000
    addresses: [ 192.0.2.9/29, 2001:db8:1::1/64 ]