The NSX Advanced Load Balancer Controller managed Security Group associated with an SE will have rules, by default, to allow both TCP port 22 (SSH) and all ICMP ingress traffic. This is useful during troubleshooting scenarios as Support personnel can directly SSH into the NSX Advanced Load Balancer SE. In certain customer environments, it might be required to further lock down TCP port 22. This topic shows how to use the NSX Advanced Load Balancer cloud wildcard_access configuration flag to achieve this extra measure of security.

Use the following CLI to list security details of the concerned security group.

Default Case in OpenStack

root@node-17:~# neutron security-group-list
+--------------------------------------+---------------------------------------------+-----------------------------------------------------+
| id                                   | name                                        | security_group_rules                                |
+--------------------------------------+---------------------------------------------+-----------------------------------------------------+
| e1e3f96e-cc9d-4fd4-bb01-4db9480621d8 | avi-se-3cf0f25c-8b25-4b6c-94db-ab59ae8f2f23 | egress, IPv4                                        |
|                                      |                                             | egress, IPv6                                        |
|                                      |                                             | ingress, IPv4, 22/tcp, remote_ip_prefix: 0.0.0.0/0  |
|                                      |                                             | ingress, IPv4, icmp, remote_ip_prefix: 0.0.0.0/0    |
+--------------------------------------+---------------------------------------------+-----------------------------------------------------+

Deactivating Port 22 Wildcard Access

The following CLI command sequence first reveals that the wildcard_access configuration is set to True, by default. Subsequent commands change it to False.

Note:

The change takes effect only for newly created SEs.

[admin:10-10-22-142]: > configure cloud avi-os
Updating an existing object. Currently, the object is:
+---------------------------+--------------------------------------------+
| Field                     | Value                                      |
+---------------------------+--------------------------------------------+
| uuid                      | cloud-c62d3177-ca44-4565-a167-62d783a34be9 |
| name                      | avi-os                                     |
| vtype                     | CLOUD_OPENSTACK                            |
| openstack_configuration   |                                            |
|   username                | admin                                      |
|   security_groups         | True                                       |
|   auth_url                | http://10.10.22.23:5000/v2.0               |
|   wildcard_access         | True                                       |

...  DETAILS OMITTED ...

| tenant_ref                | admin                                      |
+---------------------------+--------------------------------------------+
[admin:10-10-22-142]: cloud:openstack_configuration>
[admin:10-10-22-142]: cloud:openstack_configuration> no wildcard_access
[admin:10-10-22-142]: cloud:openstack_configuration> save
[admin:10-10-22-142]: cloud> save
[admin:10-10-22-142]: cloud> save
+---------------------------+--------------------------------------------+
| Field                     | Value                                      |
+---------------------------+--------------------------------------------+
| uuid                      | cloud-c62d3177-ca44-4565-a167-62d783a34be9 |
| name                      | avi-os                                     |
| vtype                     | CLOUD_OPENSTACK                            |
| openstack_configuration   |                                            |
|   username                | admin                                      |
|   security_groups         | True                                       |
|   auth_url                | http://10.10.22.23:5000/v2.0               |
|   wildcard_access         | False                                      |
...
| tenant_ref                | admin                                      |
+---------------------------+--------------------------------------------+

Confirming if Tight Security is Implemented

You can check if tight security is implemented by using the neutron security-group-list command.

root@node-17:~# neutron security-group-list
+--------------------------------------+---------------------------------------------+---------------------------------------------------+
| id                                   | name                                        | security_group_rules                              |
+--------------------------------------+---------------------------------------------+---------------------------------------------------+
| fafaf765-9d88-42d0-ae48-76b839177b52 | avi-se-095fa798-d643-4a7b-849b-910e33421f11 | egress, IPv4                                      |
|                                      |                                             | egress, IPv6                                      |
|                                      |                                             | ingress, IPv4, icmp, remote_ip_prefix: 0.0.0.0/0  |
+--------------------------------------+---------------------------------------------+---------------------------------------------------+