diff --git a/vmware_nsxlib/v3/nsx_constants.py b/vmware_nsxlib/v3/nsx_constants.py
index bbf965fa..d14461ee 100644
--- a/vmware_nsxlib/v3/nsx_constants.py
+++ b/vmware_nsxlib/v3/nsx_constants.py
@@ -110,6 +110,9 @@ LOCAL_IP_PREFIX = 'local_ip_prefix'
 
 LOGGING = 'logging'
 
+# Allowed address pairs
+NUM_ALLOWED_IP_ADDRESSES = 128
+
 # QoS directions egress/ingress
 EGRESS = 'egress'
 INGRESS = 'ingress'