From f5bb072f28cc6225310d7d295a3f35b42587336e Mon Sep 17 00:00:00 2001
From: Jeremy Stretch <jstretch@digitalocean.com>
Date: Wed, 7 Mar 2018 11:08:28 -0500
Subject: [PATCH] Fixes #1953: Ignore duplicate IPs when calculating prefix
 utilization

---
 netbox/ipam/models.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/netbox/ipam/models.py b/netbox/ipam/models.py
index d8e2aae97..714d5a5b0 100644
--- a/netbox/ipam/models.py
+++ b/netbox/ipam/models.py
@@ -365,7 +365,8 @@ class Prefix(CreatedUpdatedModel, CustomFieldModel):
             child_prefixes = netaddr.IPSet([p.prefix for p in queryset])
             return int(float(child_prefixes.size) / self.prefix.size * 100)
         else:
-            child_count = self.get_child_ips().count()
+            # Compile an IPSet to avoid counting duplicate IPs
+            child_count = netaddr.IPSet([ip.address.ip for ip in self.get_child_ips()]).size
             prefix_size = self.prefix.size
             if self.family == 4 and self.prefix.prefixlen < 31 and not self.is_pool:
                 prefix_size -= 2