add load balancer info

content/cloud/advanced-features/index.md

@@ -202,6 +202,14 @@ where **<internal_subnet_ID>** is an ID of internal subnet used by your instance
 
 For more info, please refer to [https://docs.openstack.org/octavia/train/user/guides/basic-cookbook.html#basic-lb-with-hm-and-fip](https://docs.openstack.org/octavia/train/user/guides/basic-cookbook.html#basic-lb-with-hm-and-fip).
 
+
+{{<hint info>}}
+**NOTICE:**
+
+Sometimes it can happen that Load Balancer is working but connection is not working because it is not added into security groups. So to prevent this don't forget to apply neutron security group to amphorae created on the LB network to allow traffic reaching the configured load balancer. See [the load balancer deployment walkthrough](https://docs.openstack.org/octavia/train/contributor/guides/dev-quick-start.html?highlight=security%20group#production-deployment-walkthrough) for more details.
+{{</hint>}}
+
+
 LBaaS (Load Balancer as a service) provides user with load balancing service, that can be fully managed via OpenStack API (some basic tasks are supported by GUI). Core benefits:
 * creation and management of load balancer resources can be easily automatized via API, or existing tools like Ansible or Terraform
 * applications can be easily scaled by starting up more OpenStack instances and registering them into the load balancer