Chapter 3. Common administrative networking tasks

1. In the dashboard, select Project > Network > Networks.

2. Click +Create Network and specify the following values:

   Field	Description
   Network Name	Descriptive name, based on the role that the network will perform. If you are integrating the network with an external VLAN, consider appending the VLAN ID number to the name. For example, webservers_122, if you are hosting HTTP web servers in this subnet, and your VLAN tag is 122. Or you might use internal-only if you intend to keep the network traffic private, and not integrate the network with an external network.
   Admin State	Controls whether the network is immediately available. Use this field to create the network in a Down state, where it is logically present but inactive. This is useful if you do not intend to enter the network into production immediately.

3. Click the Next button, and specify the following values in the Subnet tab:

   Field	Description
   Create Subnet	Determines whether to create a subnet. For example, you might not want to create a subnet if you intend to keep this network as a placeholder without network connectivity.
   Subnet Name	Enter a descriptive name for the subnet.
   Network Address	Enter the address in CIDR format, which contains the IP address range and subnet mask in one value. To determine the address, calculate the number of bits masked in the subnet mask and append that value to the IP address range. For example, the subnet mask 255.255.255.0 has 24 masked bits. To use this mask with the IPv4 address range 192.168.122.0, specify the address 192.168.122.0/24.
   IP Version	Specifies the internet protocol version, where valid types are IPv4 or IPv6. The IP address range in the Network Address field must match whichever version you select.
   Gateway IP	IP address of the router interface for your default gateway. This address is the next hop for routing any traffic destined for an external location, and must be within the range that you specify in the Network Address field. For example, if your CIDR network address is 192.168.122.0/24, then your default gateway is likely to be 192.168.122.1.
   Disable Gateway	Disables forwarding and isolates the subnet.

4. Click Next to specify DHCP options:

   • Enable DHCP - Enables DHCP services for this subnet. You can use DHCP to automate the distribution of IP settings to your instances.

   • IPv6 Address - Configuration Modes. If you create an IPv6 network, you must specify how to allocate IPv6 addresses and additional information:

     • No Options Specified - Select this option if you want to set IP addresses manually, or if you use a non OpenStack-aware method for address allocation.
     • SLAAC (Stateless Address Autoconfiguration) - Instances generate IPv6 addresses based on Router Advertisement (RA) messages sent from the OpenStack Networking router. Use this configuration to create an OpenStack Networking subnet with ra_mode set to slaac and address_mode set to slaac.
     • DHCPv6 stateful - Instances receive IPv6 addresses as well as additional options (for example, DNS) from the OpenStack Networking DHCPv6 service. Use this configuration to create a subnet with ra_mode set to dhcpv6-stateful and address_mode set to dhcpv6-stateful.
     • DHCPv6 stateless - Instances generate IPv6 addresses based on Router Advertisement (RA) messages sent from the OpenStack Networking router. Additional options (for example, DNS) are allocated from the OpenStack Networking DHCPv6 service. Use this configuration to create a subnet with ra_mode set to dhcpv6-stateless and address_mode set to dhcpv6-stateless.
   • Allocation Pools - Range of IP addresses that you want DHCP to assign. For example, the value 192.168.22.100,192.168.22.100 considers all up addresses in that range as available for allocation.

   • DNS Name Servers - IP addresses of the DNS servers available on the network. DHCP distributes these addresses to the instances for name resolution.

     Important

     For strategic services such as DNS, it is a best practice not to host them on your cloud. For example, if your cloud hosts DNS and your cloud becomes inoperable, DNS is unavailable and the cloud components cannot do lookups on each other.

   • Host Routes - Static host routes. First, specify the destination network in CIDR format, followed by the next hop that you want to use for routing (for example, 192.168.23.0/24, 10.1.31.1). Provide this value if you need to distribute static routes to instances.

5. Click Create.

   You can view the complete network in the Networks tab. You can also click Edit to change any options as needed. When you create instances, you can configure them now to use its subnet, and they receive any specified DHCP options.

1. In the dashboard, select Project > Network > Routers.

2. Select your virtual router name in the Routers list, and click Add Interface.

   In the Subnet list, select the name of your new subnet. You can optionally specify an IP address for the interface in this field.

3. Click Add Interface.

   Instances on your network can now communicate with systems outside the subnet.

1. In the dashboard, select Project > Network > Networks.

   Remove all router interfaces associated with the target network subnets.

   To remove an interface, find the ID number of the network that you want to delete by clicking on your target network in the Networks list, and looking at the ID field. All the subnets associated with the network share this value in the Network ID field.

2. Navigate to Project > Network > Routers, click the name of your virtual router in the Routers list, and locate the interface attached to the subnet that you want to delete.

   You can distinguish this subnet from the other subnets by the IP address that served as the gateway IP. You can further validate the distinction by ensuring that the network ID of the interface matches the ID that you noted in the previous step.

3. Click the Delete Interface button for the interface that you want to delete.
4. Select Project > Network > Networks, and click the name of your network.

5. Click the Delete Subnet button for the subnet that you want to delete.

   Note

   If you are still unable to remove the subnet at this point, ensure it is not already being used by any instances.

6. Select Project > Network > Networks, and select the network you would like to delete.
7. Click Delete Networks.

1. In the dashboard, select Project > Network > Networks.
2. Click the name of your network.
3. Select the target subnet, and click Delete Subnets.

1. In the dashboard, select Project > Network > Routers, and click Create Router.
2. Enter a descriptive name for the new router, and click Create router.
3. Click Set Gateway next to the entry for the new router in the Routers list.
4. In the External Network list, specify the network that you want to receive traffic destined for an external location.

5. Click Set Gateway.

   After you add a router, you must configure any subnets you have created to send traffic using this router. You do this by creating interfaces between the subnet and the router.

1. In the dashboard, select Project > Network > Routers, and click the name of the router that you want to delete.
2. Select the interfaces of type Internal Interface, and click Delete Interfaces.
3. From the Routers list, select the target router and click Delete Routers.

Procedure

1. Log in as the stack user on the overcloud Networking controller host and open l3_agent.conf in a text editor.

   Example

   Copy to Clipboard Toggle word wrap

   vi /var/lib/config-data/neutron/etc/neutron/l3_agent.conf

2. Locate the ha_vrrp_advert_int option, and increase the VRRP advert interval. (The default is 2 seconds.)

   Example

   Copy to Clipboard Toggle word wrap

   [DEFAULT]
   ha_vrrp_advert_int = 7
   ha_vrrp_garp_master_repeat = 5
   ha_vrrp_garp_master_delay = 5

   There are also options for gratuitous ARP messages that you can set:

   ha_vrrp_garp_master_repeat

   The number of gratuitous ARP messages to send at one time after the transition to the master state. (The default is 5 messages.)

   ha_vrrp_garp_master_delay

   The delay for second set of gratuitous ARP messages after the lower priority advert is received in the master state. (The default is 5 seconds.)

   Tip

   The next time that the openstack overcloud deploy command is run, any manual changes like this one to l3_agent.conf are overwritten. You can write a post-deployment script that re-applies your changes after future overcloud updates. If you incorporate the puppet hieradata role name described in the following document in your script, the script will run only on the overcloud node roles that must have your l3_agent.conf changes re-applied. For more information, see Post-Configuration: Customizing All Overcloud Roles in the Advanced Overcloud Customization guide.

1. In the dashboard, select Project > Network > Network Topology.
2. Locate the router that you want to manage, hover your mouse over it, and click Add Interface.

3. Specify the Subnet that you want to connect to the router.

   You can also specify an IP address. The address is useful for testing and troubleshooting purposes, since a successful ping to this interface indicates that the traffic is routing as expected.

4. Click Add interface.

   The Network Topology diagram automatically updates to reflect the new interface connection between the router and subnet.

1. In the dashboard, select Project > Network > Routers.
2. Click the name of the router that hosts the interface that you want to delete.
3. Select the interface type (Internal Interface), and click Delete Interfaces.

Procedure

1. In the dashboard, select Admin > Networks > Create Network > Project.
2. Select the project that you want to host the new network with the Project drop-down list.

3. Review the options in Provider Network Type:

   • Local - Traffic remains on the local Compute host and is effectively isolated from any external networks.
   • Flat - Traffic remains on a single network and can also be shared with the host. No VLAN tagging or other network segregation takes place.
   • VLAN - Create a network using a VLAN ID that corresponds to a VLAN present in the physical network. This option allows instances to communicate with systems on the same layer 2 VLAN.
   • GRE - Use a network overlay that spans multiple nodes for private communication between instances. Traffic egressing the overlay must be routed.
   • VXLAN - Similar to GRE, and uses a network overlay to span multiple nodes for private communication between instances. Traffic egressing the overlay must be routed.

4. Click Create Network.

   Review the Project Network Topology to validate that the network has been successfully created.

Procedure

1. Enter the following command to allocate a floating IP address from the pool. In this example, the network is named public.

   Example

   Copy to Clipboard Toggle word wrap

   $ openstack floating ip create public

   Sample output

   In the following example, the newly allocated floating IP is 192.0.2.200. You can assign it to an instance.

   Copy to Clipboard Toggle word wrap

   +---------------------+--------------------------------------------------+
   | Field               | Value                                            |
   +---------------------+--------------------------------------------------+
   | fixed_ip_address    | None                                             |
   | floating_ip_address | 192.0.2.200                                      |
   | floating_network_id | f0dcc603-f693-4258-a940-0a31fd4b80d9             |
   | id                  | 6352284c-c5df-4792-b168-e6f6348e2620             |
   | port_id             | None                                             |
   | router_id           | None                                             |
   | status              | ACTIVE                                           |
   +---------------------+--------------------------------------------------+

2. Enter the following command to locate your instance:

   Copy to Clipboard Toggle word wrap

   $ openstack server list

   Sample output

   Copy to Clipboard Toggle word wrap

   +-------------+-------------+--------+-------------+-------+-------------+
   | ID          | Name        | Status | Networks    | Image | Flavor      |
   +-------------+-------------+--------+-------------+-------+-------------+
   | aef3ca09-88 | prod-serv1  | ACTIVE | public=198. | rhel8 | review-     |
   | 7d-4d20-872 |             |        | 51.100.56   |       | ephemeral   |
   | d-1d1b49081 |             |        |             |       |             |
   | 958         |             |        |             |       |             |
   |             |             |        |             |       |             |
   +-------------+-------------+--------+-------------+-------+-------------+

3. Associate the instance name or ID with the floating IP.

   Example

   Copy to Clipboard Toggle word wrap

   $ openstack server add floating ip prod-serv1 192.0.2.200

Procedure

1. Open /etc/sysconfig/network-scripts/ifcfg-eth0 in a text editor, and update the following parameters with values appropriate for the network at your site:

   • IPADDR
   • NETMASK GATEWAY

   • DNS1 (name server)

     Here is an example:

     Copy to Clipboard Toggle word wrap

     # vi /etc/sysconfig/network-scripts/ifcfg-eth0
     DEVICE=eth0
     TYPE=OVSPort
     DEVICETYPE=ovs
     OVS_BRIDGE=br-ex
     ONBOOT=yes

2. Open /etc/sysconfig/network-scripts/ifcfg-br-ex in a text editor and update the virtual bridge parameters with the IP address values that were previously allocated to eth0:

   Copy to Clipboard Toggle word wrap

   # vi /etc/sysconfig/network-scripts/ifcfg-br-ex
   DEVICE=br-ex
   DEVICETYPE=ovs
   TYPE=OVSBridge
   BOOTPROTO=static
   IPADDR=192.168.120.10
   NETMASK=255.255.255.0
   GATEWAY=192.168.120.1
   DNS1=192.168.120.1
   ONBOOT=yes

   You can now assign floating IP addresses to instances and make them available to the physical network.

Procedure

1. Log in to the undercloud as the stack user, and source the stackrc file to enable the director command line tools.

   Example

   Copy to Clipboard Toggle word wrap

   $ source ~/stackrc

2. Create a custom YAML environment file (my-neutron-environment.yaml).

   Note

   Values inside parentheses are sample values that are used in the example commands in this procedure. Substitute these sample values with ones that are appropriate for your site.

   Example

   Copy to Clipboard Toggle word wrap

   $ vi /home/stack/templates/my-neutron-environment.yaml

   Tip

   The undercloud includes a set of Orchestration service templates that form the plan for your overcloud creation. You can customize aspects of the overcloud with environment files, which are YAML-formatted files that override parameters and resources in the core Orchestration service template collection. You can include as many environment files as necessary.

3. In the environment file, add a parameter_defaults section. Under this section, add the dns_domain for ports extension, dns_domain_ports.

   Example

   Copy to Clipboard Toggle word wrap

   parameter_defaults:
     NeutronPluginExtensions: "qos,port_security,dns_domain_ports"

   Note

   If you set dns_domain_ports, ensure that the deployment does not also use dns_domain, the DNS Integration extension. These extensions are incompatible, and both extensions cannot be defined simultaneously.

4. Also in the parameter_defaults section, add your domain name (example.com) using the NeutronDnsDomain parameter.

   Example

   Copy to Clipboard Toggle word wrap

   parameter_defaults:
       NeutronPluginExtensions: "qos,port_security,dns_domain_ports"
       NeutronDnsDomain: "example.com"

5. Run the openstack overcloud deploy command and include the core Orchestration templates, environment files, and this new environment file.

   Important

   The order of the environment files is important because the parameters and resources defined in subsequent environment files take precedence.

   Example

   Copy to Clipboard Toggle word wrap

   $ openstack overcloud deploy --templates \
   -e [your-environment-files] \
   -e /usr/share/openstack-tripleo-heat-templates/environments/services/my-neutron-environment.yaml

Verification steps

1. Log in to the overcloud, and create a new port (new_port) on a network (public). Assign a DNS name (my_port) to the port.

   Example

   Copy to Clipboard Toggle word wrap

   $ source ~/overcloudrc
   $ openstack port create --network public --dns-name my_port new_port

2. Display the details for your port (new_port).

   Example

   Copy to Clipboard Toggle word wrap

   $ openstack port show -c dns_assignment -c dns_domain -c dns_name -c name new_port

   Output

   Copy to Clipboard Toggle word wrap

   +-------------------------+----------------------------------------------+
   | Field                   | Value                                        |
   +-------------------------+----------------------------------------------+
   | dns_assignment          | fqdn='my_port.example.com',                  |
   |                         | hostname='my_port',                          |
   |                         | ip_address='10.65.176.113'                   |
   | dns_domain              | example.com                                  |
   | dns_name                | my_port                                      |
   | name                    | new_port                                     |
   +-------------------------+----------------------------------------------+

   Under dns_assignment, the fully qualified domain name (fqdn) value for the port contains a concatenation of the DNS name (my_port) and the domain name (example.com) that you set earlier with NeutronDnsDomain.

3. Create a new VM instance (my_vm) using the port (new_port) that you just created.

   Example

   Copy to Clipboard Toggle word wrap

   $ openstack server create --image rhel --flavor m1.small --port new_port my_vm

4. Display the details for your port (new_port).

   Example

   Copy to Clipboard Toggle word wrap

   $ openstack port show -c dns_assignment -c dns_domain -c dns_name -c name new_port

   Output

   Copy to Clipboard Toggle word wrap

   +-------------------------+----------------------------------------------+
   | Field                   | Value                                        |
   +-------------------------+----------------------------------------------+
   | dns_assignment          | fqdn='my_vm.example.com',                    |
   |                         | hostname='my_vm',                            |
   |                         | ip_address='10.65.176.113'                   |
   | dns_domain              | example.com                                  |
   | dns_name                | my_vm                                        |
   | name                    | new_port                                     |
   +-------------------------+----------------------------------------------+

   Note that the Compute service changes the dns_name attribute from its original value (my_port) to the name of the instance with which the port is associated (my_vm).

Procedure

1. Log in to the undercloud host as the stack user.

2. Source the undercloud credentials file:

   Copy to Clipboard Toggle word wrap

   $ source ~/stackrc

3. Create a custom YAML environment file.

   Example

   Copy to Clipboard Toggle word wrap

   $ vi /home/stack/templates/my-octavia-environment.yaml

4. Your environment file must contain the keywords parameter_defaults. Under these keywords, add the extra DHCP option extension, extra_dhcp_opt.

   Example

   Copy to Clipboard Toggle word wrap

   parameter_defaults:
     NeutronPluginExtensions: "qos,port_security,extra_dhcp_opt"

5. Run the deployment command and include the core heat templates, environment files, and this new custom environment file.

   Copy to Clipboard Toggle word wrap

   The order of the environment files is important because the parameters and resources defined in subsequent environment files take precedence.

   Example

   Copy to Clipboard Toggle word wrap

   $ openstack overcloud deploy --templates \
   -e <your_environment_files> \
   -e /usr/share/openstack-tripleo-heat-templates/environments/services/octavia.yaml \
   -e /home/stack/templates/my-octavia-environment.yaml

Verification

1. Source your credentials file.

   Example

   Copy to Clipboard Toggle word wrap

   $ source ~/overcloudrc

2. Create a new port (new_port) on a network (public). Assign a valid attribute from the DHCP specification to the new port.

   Example

   Copy to Clipboard Toggle word wrap

   $ openstack port create --extra-dhcp-option name=domain-name,value=test.domain --extra-dhcp-option name=ntp-server,value=192.0.2.123 --network public new_port

3. Display the details for your port (new_port).

   Example

   Copy to Clipboard Toggle word wrap

   $ openstack port show new_port -c extra_dhcp_opts

   Sample output

   Copy to Clipboard Toggle word wrap

   +-----------------+--------------------------------------------------------------------+
   | Field           | Value                                                              |
   +-----------------+--------------------------------------------------------------------+
   | extra_dhcp_opts | ip_version='4', opt_name='domain-name', opt_value='test.domain'    |
   |                 | ip_version='4', opt_name='ntp-server', opt_value='192.0.2.123'     |
   +-----------------+--------------------------------------------------------------------+

Procedure

1. On the undercloud host, logged in as the stack user, create a custom YAML environment file.

   Example

   Copy to Clipboard Toggle word wrap

   $ vi /home/stack/templates/my-modules-environment.yaml

   Tip

   Heat uses a set of plans called templates to install and configure your environment. You can customize aspects of the overcloud with a custom environment file, which is a special type of template that provides customization for your heat templates.

2. In the YAML environment file under parameter_defaults, set ExtraKernelModules to the name of the module that you want to load.

   Example

   Copy to Clipboard Toggle word wrap

   ComputeParameters:
     ExtraKernelModules:
       nf_conntrack_proto_gre: {}
   ControllerParameters:
     ExtraKernelModules:
       nf_conntrack_proto_gre: {}

3. Run the openstack overcloud deploy command and include the core heat templates, environment files, and this new custom environment file.

   Important

   The order of the environment files is important as the parameters and resources defined in subsequent environment files take precedence.

   Example

   Copy to Clipboard Toggle word wrap

   $ openstack overcloud deploy --templates \
   -e [your-environment-files] \
   -e /usr/share/openstack-tripleo-heat-templates/environments/services/my-modules-environment.yaml