Flexible Network Interfaces

A flexible network interface is a networking component in a Data-center that generally represents a virtual network interface card. It is the point of interconnection between a computer and a private or public network. Network interface can have the attributes below:

  • A primary private IPv4 address from the IPv4 address range of your Data-center

  • A single or multiple secondary private IPv4 addresses from the IPv4 address range of your Data-center

  • O floating IP address (IPv4) per private IPv4 address

  • One public IPv4 address

  • A single or multiple security groups

  • A MAC address

  • A source/destination check flag

  • A description

You can create and configure network interfaces in your NCS account and attach them to instances in your Data-center.

Contents

Network interface basics

You can create a network interface, attach it to an instance, detach it from an instance, and attach it to another instance. The attributes of a network interface follow it as it's attached or detached from an instance and reattached to another instance. When you move a network interface from one instance to another, network traffic is redirected to the new instance.

Primary network interface

Each instance has a default network interface, called the primary network interface. You cannot detach a primary network interface from an instance. You can create and attach additional network interfaces.

Public IPv4 addresses for network interfaces

In a Data-center, all subnets have a modifiable attribute that determines whether network interfaces created in that subnet ( and instances launched into that subnet) are assigned a public IPv4 address.The public IPv4 address is assigned from Nobus's pool of public IPv4 addresses. When you launch an instance, the IP address is assigned to the primary network interface that's created.

When you create a network interface, it inherits the public IPv4 addressing attribute from the subnet. If you later modify the public IPv4 addressing attribute of the subnet, the network interface keeps the setting that was in effect when it was created. If you launch an instance and specify an existing network interface as the primary network interface, the public IPv4 address attribute is determined by this network interface.

floating IP addresses for network interface

If you have A floating IP address, you can associate it with one of the private IPv4 addresses for the network interface. You can only associate one floating IP address with each private IPv4 address.

If you disassociate A floating IP address from a network interface, you can release it back to the address pool. This is the only way to associate A floating IP address with another instance in a different subnet or Data-center, since network interfaces are specific to subnets.

Source/destination checking

Disabling source/destination checking enables an instance to handle network traffic that isn't specifically destined for the instance. For example, instances running services such as network address translation, routing, or a firewall should disable the source/destination check attribute. This attribute is enabled by default.

Working with network interfaces

You can work with network interfaces using the Nobus FCS console

Contents

Creating a network interface

You can create a network interface in a subnet. You can't move the network interface to another subnet after it's created, and you can only attach the network interface to instances in the same Availability Zone.

To create a network interface using the console

  1. log in to the Nobus Management Console.

  2. On the Project tab, open the Network tab and click Networks

  3. Click Create Network.

  4. In the Create Network dialog box, specify the following values.

    Network tab

    Network Name: Specify a name to identify the network.

    Shared: Share the network with other projects. Non admin users are not allowed to set shared option.

    Admin State: The state to start the network in.

    Create Subnet: Select this check box to create a subnet

    You do not have to specify a subnet when you create a network, but if you do not specify a subnet, the network can not be attached to an instance.

    Subnet tab

    Subnet Name: Specify a name for the subnet.

    Network Address: Specify the IP address for the subnet.

    IP Version: Select IPv4

    Gateway IP: Specify an IP address for a specific gateway. This parameter is optional.

    Disable Gateway: Select this check box to disable a gateway IP address.

    Subnet Details tab

    Enable DHCP: Select this check box to enable DHCP.

    Allocation Pools: Specify IP address pools.

    DNS Name Servers: Specify a name for the DNS server.

    Host Routes: Specify the IP address of host routes.

  5. Click Create.

    The dashboard shows the network on the Networks tab.

Viewing details about a network interface

You can view all the network interfaces in your account.

To View a network interface using the console

  1. log in to the Nobus Management Console.

  2. Goto Project > Network > Networks

  3. Locate and click on the network interface to view the details

Attaching a network interface to an instance

You can attach a network interface to any of your stopped or running instances, using either the Instances or Network Interfaces section of the Nobus FCS console. You can also specify an existing network interface or attach an additional network interface when you launch an instance.

If the public IPv4 address on your instance is released, it does not receive a new one if there is more than one network interface attached to the instance. For more information see Public IPv4 addresses and external DNS hostnames.

To attach a network interface to an instance from the instance console

  1. log in to the Nobus Management Console.

  2. Goto Project > Compute > Instance

  3. Locate the instance.

  4. Choose Actions, select Attach interface.

  5. Select a network interface.

  6. Choose Attach.

Detaching a network interface from an instance

You can detach a secondary network interface that is attached to an FCS instance at any time, using the Instances page.

To detach a network interface from an instance

  1. To create an instance, log in to the Nobus Management Console.

  2. Goto Project > Compute > Instance

  3. Locate the instance.

  4. Choose Actions and select Detach interface.

  5. Select the network interface and choose Detach.

You can't use the Nobus FCS console to detach a network interface that is attached to a resource from another service. The network interfaces for those resources are deleted when the resource is deleted.

Modifying a network interface

To modify a network interface

  1. To create an instance, log in to the Nobus Management Console.

  2. Goto Project > Network > Networks

  3. Locate the network.

  4. Choose Actions and select Edit Network.

  5. Edit the network details and click Save.

Deleting a network interface

To delete an instance, you must first detach the network interface. Deleting a network interface releases all attributes associated with the interface and releases any private IP addresses or floating IP addresses to be used by another instance.

To delete a network interface using the console

  1. log in to the Nobus Management Console.

  2. Goto Project > Network > Networks

  3. Select a network interface and click on the Delete Networks button.

  4. In the Delete Networks dialog box, choose Delete.