#6934: Correct prefix utilization and available IP reporting to account for child IP ranges

docs/release-notes/version-3.0.md

@@ -15,6 +15,7 @@
 * [#6846](https://github.com/netbox-community/netbox/issues/6846) - Form-driven REST API calls should use brief mode
 * [#6871](https://github.com/netbox-community/netbox/issues/6871) - Support dynamic tag types in GraphQL API
 * [#6894](https://github.com/netbox-community/netbox/issues/6894) - Fix available IP generation for prefix assigned to a VRF
+* [#6934](https://github.com/netbox-community/netbox/issues/6934) - Correct prefix utilization and available IP reporting to account for child IP ranges
 * [#6953](https://github.com/netbox-community/netbox/issues/6953) - Remove change log tab from non-applicable object views
 
 ---

netbox/ipam/models/ip.py

@@ -435,7 +435,10 @@ class Prefix(PrimaryModel):
 
         prefix = netaddr.IPSet(self.prefix)
         child_ips = netaddr.IPSet([ip.address.ip for ip in self.get_child_ips()])
-        available_ips = prefix - child_ips
+        child_ranges = netaddr.IPSet()
+        for iprange in self.get_child_ranges():
+            child_ranges.add(iprange.range)
+        available_ips = prefix - child_ips - child_ranges
 
         # IPv6, pool, or IPv4 /31-/32 sets are fully usable
         if self.family == 6 or self.is_pool or (self.family == 4 and self.prefix.prefixlen >= 31):

netbox/ipam/tests/test_models.py

@@ -142,17 +142,17 @@ class TestPrefix(TestCase):
             IPAddress(address=IPNetwork('10.0.0.3/26')),
             IPAddress(address=IPNetwork('10.0.0.5/26')),
             IPAddress(address=IPNetwork('10.0.0.7/26')),
-            IPAddress(address=IPNetwork('10.0.0.9/26')),
-            IPAddress(address=IPNetwork('10.0.0.11/26')),
-            IPAddress(address=IPNetwork('10.0.0.13/26')),
         ))
+        IPRange.objects.create(
+            start_address=IPNetwork('10.0.0.9/26'),
+            end_address=IPNetwork('10.0.0.12/26')
+        )
         missing_ips = IPSet([
             '10.0.0.2/32',
             '10.0.0.4/32',
             '10.0.0.6/32',
             '10.0.0.8/32',
-            '10.0.0.10/32',
-            '10.0.0.12/32',
+            '10.0.0.13/32',
             '10.0.0.14/32',
         ])
         available_ips = parent_prefix.get_available_ips()