HP Integrity Virtual Machines Release Notes

7 Networking Information
This section contains notes about configuring networks for virtual machines.
7.1 Vswitches Are Always in SHARED Mode
The hpvmnet command displays the status of the vswitches, including the mode. The vswitches
are always in SHARED mode. No other modes are supported at this time.
7.2 Do Not Use the HP A5506B PCI 10/100Base-TX 4 Port Interface for
Virtual Networking
Host to guest connectivity may not be reliable when using the HP A5506B PCI 10/100Base-TX 4
Port interface for guest networking.
7.3 MAC Address Validation Can Be Enhanced
When you add a virtual NIC to your guest, Integrity VM checks to make sure the MAC address
is unique.
By default, Integrity VM makes three attempts (each with a one-second timeout) to determine
the validity of the MAC address for the virtual NIC. This process can result in up to ten seconds
of delay for each defined virtual NIC. To speed up this processing, add the following tunable to
the /etc/rc.config.d/hpvmconf configuration file:
HPVMMACADDRFRAMES=n
Where n is the number of attempts (1 to 30). The default is 3. A value of 1 or 2 increases
performance at the risk of missing a response from a slow NIC.
Do not set the HPVMMACADDRFRAMES tunable to 0. Setting this tunable to 0 results in a
virtual NIC with a MAC address that is the same as another virtual or physical NIC. The first
guest to boot obtains the MAC address; the guest with the duplicate MAC address fails to boot.
To boost virtual network performance, create additional vswitches and allocate them across
guests.
7.4 Auto Port Aggregation (APA) is Supported on the VM Host, Not on
the Guest
Integrity VM does not support running APA on a guest. You can run APA on the VM Host.
APA can be configured on the VM Host to provide a highly available LAN for the vswitch (APA
in active/passive mode) or to increase the bandwidth of the vswitch LAN (APA active/active
mode). Before you stop APA, use the hpvmnet -h command to halt the vswitch. If you do not
halt the vswitch first, the hpvmnet command reports an incorrect MAC address for the vswitch.
7.5 Do Not Run Applications that Set Network Devices into Promiscuous
Mode
Vswitches must not be connected to network devices that are set to promiscuous mode. Do not
run applications like tcpdump on the VM Host on interfaces that are used for virtual switches.
7.6 Do not Turn on Checksum Offloading (CKO) on the Physical Network
Interface Backing the Vswitch
Checksum offloading (CKO) is turned off by default on physical network interfaces used as
backing for the vswitch. Do not turn on CKO on from the guest using a remote command, such
as remsh. The operation hangs and interrupts the guest network.
7.1 Vswitches Are Always in SHARED Mode 43