Product Documentation

Configuring IP Addresses

Oct 30, 2012

The NIC used as the management interface on a managed server is initially specified during XenServer installation. In XenCenter, the XenServer xe command line interface (CLI), and any other management software running on separate machines all connect to the server via the IP address of the management interface.

If a server has two or more NICs, you can select a different NIC or NIC bond to use as its management interface. You can assign IP addresses to NICs (also known as configuring secondary interface) and dedicate NICs to a specific function, such as storage or other types of network traffic. Note that putting the management interface on a VLAN network is not supported.

Note also that when a new server joins a pool, the pool master's networking configuration, including network and bond information, is automatically inherited by the joining server. However, the joining server's management interface will not be changed to match the master, so you will need to reconfigure it after joining in order to use the same bond as the pool master server. Note also that a server with its management interface on a bond will not be permitted to join a pool, and so you will need to reconfigure the server's management interface and move it back on to a physical NIC before it can join a pool.

The following sections provide instructions to assign an IP address to a NIC and change the management interface for a server or pool in XenCenter, using the Configure IP Addresses dialog box.

To assign an IP address to a NIC

You can use XenCenter to configure a NIC an IP address to carry out a specific function, such as storage traffic. When you configure a NIC with an IP address, you will be essentially creating a secondary interface.

To maintain a flexible and secure network, you can segment network traffic by creating secondary interfaces that use a dedicated NIC, for example, to establish separate networks for server management, application production traffic, and storage traffic. In the default XenServer networking configuration, all network traffic to IP-based storage devices occurs over the NIC used for the management interface. Also, it is important to note that the secondary interfaces inherit the DNS server settings from the management interface.

Assigning an IP address to a NIC, to carry out a specific function, requires that the appropriate network configuration be in place in order to ensure the NIC is used for the desired traffic. For example, to dedicate a NIC to storage traffic, you must assign the newly created interface an IP address that (a) is on the same subnet as the storage controller, if applicable, (b) is on a different subnet than the management interface, and (c) is not on the same subnet as any other secondary interfaces. Also, the NIC, storage target, switch, and/or VLAN must be configured such that the target is only accessible over the assigned NIC. This allows use of standard IP routing to control how traffic is routed between multiple NICs within a managed server.

Perform the following tasks to assign an IP address to a NIC and create a secondary interface:

  1. On the Networking tab for a server or pool, under IP Address Configuration, click Configure.
  2. Click Add IP address.
  3. Enter a name for the new secondary interface.
  4. Choose a XenServer network from the Network list.
  5. Configure the networking settings for the new interface:
    • To use automated Dynamic Host Configuration Protocol (DHCP) to automatically assign networking settings including the IP address, subnet mask and gateway, select Automatically obtain network settings using DHCP.
    • To configure networking settings manually, click Use these settings and enter the required values. You must enter an IP address and a subnet mask, but the gateway settings are optional.
  6. To configure additional interfaces, click Add IP address again and repeat the configuration steps above.
  7. When you have finished, click OK to save your configuration choices.
    Note: If you choose to configure the network settings manually, you will be prompted to confirm your settings. Click Reconfigure anyway to confirm.

To remove a secondary interface

  1. On the Networking tab for a server or pool, under IP Address Configuration, click Configure.
  2. In the list of configured interfaces on the left of the dialog box, select the one you want to remove and then click Remove this Interface.
  3. Click OK to save your configuration choices.

To change the management interface

  1. On the Networking tab for a server or pool, under IP Address Configuration, click Configure.
  2. On the Primary tab, choose a XenServer network from the Network list.
  3. Configure the networking settings for the management interface:
    • To use automated Dynamic Host Configuration Protocol (DHCP) to automatically assign network settings including the IP address, subnet mask, gateway and DNS server, select Automatically obtain network settings using DHCP.
    • To configure network settings manually, click Use these settings and enter the required values. You must enter an IP address and a subnet mask, but the gateway and DNS server settings are optional.
  4. When you have finished, click OK to save your configuration choices.
    Note: If you choose to configure the network settings manually, you will be prompted to confirm your settings. Click Reconfigure anyway to confirm.