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Oracle VM Server for SPARC 2.1 Administration Guide     Oracle VM Server for SPARC
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Part I Oracle VM Server for SPARC 2.1 Software

1.  Overview of the Oracle VM Server for SPARC Software

2.  Installing and Enabling Software

3.  Security

4.  Setting Up Services and the Control Domain

5.  Setting Up Guest Domains

6.  Setting Up I/O Domains

7.  Using Virtual Disks

8.  Using Virtual Networks

Introduction to a Virtual Network

Virtual Switch

Virtual Network Device

Inter-Vnet LDC Channels

Virtual Device Identifier and Network Interface Name

Find Oracle Solaris OS Network Interface Name

Assigning MAC Addresses Automatically or Manually

Range of MAC Addresses Assigned to Logical Domains

Automatic Assignment Algorithm

Duplicate MAC Address Detection

Freed MAC Addresses

Using Network Adapters With Logical Domains

Determine If a Network Adapter Is GLDv3-Compliant

Configuring Virtual Switch and Service Domain for NAT and Routing

Set Up the Virtual Switch to Provide External Connectivity to Domains

Configuring IPMP in a Logical Domains Environment

Configuring Virtual Network Devices Into an IPMP Group in a Domain

Configuring and Using IPMP in the Service Domain

Using Link-Based IPMP in Logical Domains Virtual Networking

Configure Physical Link Status Updates

Configuring and Using IPMP in Releases Prior to Logical Domains 1.3

Configuring IPMP in the Guest Domain

Configuring IPMP in the Service Domain

Using VLAN Tagging



Assign VLANs to a Virtual Switch and Virtual Network Device

Install a Guest Domain When the Install Server Is in a VLAN

Using NIU Hybrid I/O

Configure a Virtual Switch With an NIU Network Device

Enable Hybrid Mode

Disable Hybrid Mode

Using Link Aggregation With a Virtual Switch

Configuring Jumbo Frames

Configure Virtual Network and Virtual Switch Devices to Use Jumbo Frames

Compatibility With Older (Jumbo-Unaware) Versions of the vnet and vsw Drivers

9.  Migrating Domains

10.  Managing Resources

11.  Managing Configurations

12.  Performing Other Administration Tasks

Part II Optional Oracle VM Server for SPARC Software

13.  Oracle VM Server for SPARC Physical-to-Virtual Conversion Tool

14.  Oracle VM Server for SPARC Configuration Assistant

15.  Using the Oracle VM Server for SPARC Management Information Base Software

16.  Logical Domains Manager Discovery

17.  Using the XML Interface With the Logical Domains Manager



Assigning MAC Addresses Automatically or Manually

You must have enough media access control (MAC) addresses to assign to the number of logical domains, virtual switches, and virtual networks you are going to use. You can have the Logical Domains Manager automatically assign MAC addresses to a logical domain, a virtual network (vnet), and a virtual switch (vsw), or you can manually assign MAC addresses from your own pool of assigned MAC addresses. The ldm subcommands that set MAC addresses are add-domain, add-vsw, set-vsw, add-vnet, and set-vnet. If you do not specify a MAC address in these subcommands, the Logical Domains Manager assigns one automatically.

The advantage to having the Logical Domains Manager assign the MAC addresses is that it utilizes the block of MAC addresses dedicated for use with logical domains. Also, the Logical Domains Manager detects and prevents MAC address collisions with other Logical Domains Manager instances on the same subnet. This frees you from having to manually manage your pool of MAC addresses.

MAC address assignment happens as soon as a logical domain is created or a network device is configured into a domain. In addition, the assignment is persistent until the device, or the logical domain itself, is removed.

Range of MAC Addresses Assigned to Logical Domains

Logical Domains have been assigned the following block of 512K MAC addresses:

00:14:4F:F8:00:00 ~ 00:14:4F:FF:FF:FF

The lower 256K addresses are used by the Logical Domains Manager for automatic MAC address allocation, and you cannot manually request an address in this range:

00:14:4F:F8:00:00 - 00:14:4F:FB:FF:FF

You can use the upper half of this range for manual MAC address allocation:

00:14:4F:FC:00:00 - 00:14:4F:FF:FF:FF

Automatic Assignment Algorithm

When you do not specify a MAC address in creating logical domain or a network device, the Logical Domains Manager automatically allocates and assigns a MAC address to that logical domain or network device. To obtain this MAC address, the Logical Domains Manager iteratively attempts to select an address and then checks for potential collisions.

Before selecting a potential address, the Logical Domains Manager first looks to see if it has a recently freed, automatically assigned address saved in a database for this purpose (see Freed MAC Addresses). If so, the Logical Domains Manager selects its candidate address from the database.

If no recently freed addresses are available, the MAC address is randomly selected from the 256K range of addresses set aside for this purpose. The MAC address is selected randomly to lessen the chance of a duplicate MAC address being selected as a candidate.

The address selected is then checked against other Logical Domains Managers on other systems to prevent duplicate MAC addresses from actually being assigned. The algorithm employed is described in Duplicate MAC Address Detection. If the address is already assigned, the Logical Domains Manager iterates, choosing another address, and again checking for collisions. This continues until a MAC address is found that is not already allocated, or a time limit of 30 seconds has elapsed. If the time limit is reached, then the creation of the device fails, and an error message similar to the following is shown.

Automatic MAC allocation failed.  Please set the vnet MAC address manually.

Duplicate MAC Address Detection

To prevent the same MAC address from being allocated to different devices, one Logical Domains Manager checks with other Logical Domains Managers on other systems by sending a multicast message over the control domain's default network interface, including the address that the Logical Domains Manager wants to assign to the device. The Logical Domains Manager attempting to assign the MAC address waits for one second for a response back. If a different device on another Logical Domains-enabled system has already been assigned that MAC address, the Logical Domains Manager on that system sends back a response containing the MAC address in question. If the requesting Logical Domains Manager receives a response, it knows the chosen MAC address has already been allocated, chooses another, and iterates.

By default, these multicast messages are sent only to other managers on the same subnet; the default time-to-live (TTL) is 1. The TTL can be configured using the Service Management Facilities (SMF) property ldmd/hops.

Each Logical Domains Manager is responsible for:

If the Logical Domains Manager on a system is shut down for any reason, duplicate MAC addresses could occur while the Logical Domains Manager is down.

Automatic MAC allocation occurs at the time the logical domain or network device is created and persists until the device or the logical domain is removed.

Note - A detection check for duplicate MAC addresses is performed when the logical domain or network device is created, and the logical domain is started.

Freed MAC Addresses

When a logical domain or a device associated with an automatic MAC address is removed, that MAC address is saved in a database of recently freed MAC addresses for possible later use on that system. These MAC addresses are saved to prevent the exhaustion of Internet Protocol (IP) addresses from a Dynamic Host Configuration Protocol (DHCP) server. When DHCP servers allocate IP addresses, they do so for a period of time (the lease time). The lease duration is often configured to be quite long, generally hours or days. If network devices are created and removed at a high rate without the Logical Domains Manager reusing automatically allocated MAC addresses, the number of MAC addresses allocated could soon overwhelm a typically configured DHCP server.

When the Logical Domains Manager is requested to automatically obtain a MAC address for a logical domain or network device, it first looks to the freed MAC address database to see if there is a previously assigned MAC address it can reuse. If there is a MAC address available from this database, the duplicate MAC address detection algorithm is run. If the MAC address had not been assigned to someone else since it was previously freed, it will be reused and removed from the database. If a collision is detected, the address is simply removed from the database. The Logical Domains Manager then either tries the next address in the database or if none is available, randomly picks a new MAC address.