Add RHOSP egress IP information

Author: tmalove

modules/nw-egress-router-about.adoc

@@ -98,6 +98,13 @@ If you deploy {product-title} on {rh-openstack}, you must allow traffic from the
 $ openstack port set --allowed-address \
   ip_address=<ip_address>,mac_address=<mac_address> <neutron_port_uuid>
 ----
+[NOTE]
+====
+The {rh-openstack} egress IP address feature creates a neutron reservation port called `egressip-<IP address>`.
+When an egress IP address on an OpenStack network is moved from one node to another, because of a node failover for example, the neutron reservation port is removed and recreated. As a result, a floating IP address might be bound to the port, creating a SNAT mapping of the egress IP address to a public IP address. Because SNAT breaks the floating IP address, a system administrator must recreate the floating IP address.
+====
+
+
 
 {rh-virtualization-first}::