Install OpenStack – network settings (part.2)

Install OpenStack – network settings (part.2)

Use administer account (admin) to log-in OpenStack, go to

Since there has no network configurations now, we need to create a new external network.

The needed network settings are listed below:
External network
Name: ExternalNet
Subnet Name: ExternalSubNet
Network Address:
Allocation Pool:,
Other:IPV4, No DHCP, External Network, Flat Network, Assign to Admin project

Customized network
Network Name: PrivateNet
Subnet Name: PrivateSubnet
Network Address:
Gateway: (Default)
Other:DHCP, IPV4

When creating external network, we can find “Create Network” function under admin/Network/Networks page. Click it and you can find the page to create a new network.

Input the network name and select the project which this network will locate in. Use the settings in the above figure and the result will look like the following figure.

It is easy to understand besides extnet in Physical Network. The reason is that it has already been configured before deploying by the Neutron configuration. After the deployment, it will correspond to Bridge in the configuration.

The second page is the settings of Subnet. We need to provide the corresponding Subnet information here. The Subnet Name can be defined by our need, but other information needs to be consistent with previous environmental information.

After adding the above information and configurations, it will look like the following figure.

The last page is some additional attributes for the subnet. We need to check the following conditions:

  1. Do not enable DHCP
  2. Use IP addresses only between to
  3. Do not use DNS

The following figure shows the settings.

The external network will be created after clicking the create button.

In OpenStack, it is really flexible for users to customize networks. In this article, we will use VxLAN in openVswitch to demonstrate. The networks need to be defined early in OpenStack, and it will be a vast project if it needs to be changed.

Now we can log into admin project to check user’s network settings. If you know how to create projects and users, it is recommended that modifying network settings in other projects. We will have other sections to discuss this concept later.

First, switch to Project / Network / Networks label

Click Create Network and insert the above information in Create Network page

Type the customized network name

Here, we do not need to enter Gateway IP. We can use the default value, which is the first IP address. After the network being created, it will be

Leave the allocation pools blank and enable DHCP. Set-up DNS address and click the Create button.

After creating the network, we will be redirected to Networks page. We can check if we create the network successfully here.

Since there has no routers for connecting external networks, we need to move to Project / Network / Routers label to create routers.

Click Create Router button, input necessary information and choose external network.

Check if the router has been created.

Check connecting status.

Check if the type is External Gateway in Interfaces page

We need to specify and connect a subnet to the router here.

Choose a network

Submit, the status of the network will be Down for seconds.

Refresh the page and the status will be Active.

Check if the router gateway works by Ping command.

Now, the network settings are all done. Users can define networks based on their needs. Admins only need to distribute specific float IP addresses to users. The next article will discuss how to upload images (iso files), create virtual machines and log into virtual machines via float IP.

Here are other installation references:

Install OpenStack – network settings

Install OpenStack – Packstack (II)

Install OpenStack – Packstack (I)


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