The DHCP lease is renewed on a virtual machine when you restore the lease from a "Saved" state in Virtual Server 2005 (840321)

INTRODUCTION

In Microsoft Virtual Server 2005, if you configure a virtual machine to obtain an IP address from a DHCP server, the virtual machine requests an IP address, or DHCP lease. The DHCP lease is assigned after the virtual machine starts.

However, if the virtual machine is set to the Saved state, the DHCP lease may expire during the Saved state period. When the virtual machine is restored from the Saved state, Virtual Server 2005 will renew the DHCP lease.

MORE INFORMATION

To verify that a virtual machine renews its expired DHCP lease when the virtual machine is restored from the Saved state, use the ipconfig /all command. Use the command to view the "Lease Obtained" and "Lease Expires" times before and after the Saved state period.

To verify that the DHCP lease is renewed on your virtual machine, follow these steps:

At a command prompt, type ipconfig /all Drive_Letter:\Ipconfig-before.txt, where Drive_Letter is a drive on your virtual machine. Press ENTER.

Open the Ipconfig-before.txt file in Notepad.

You will see text that is similar to the following:

Windows 2000 IP Configuration

        Host Name . . . . . . . . . . . . : ew2kprs4
        Primary DNS Suffix  . . . . . . . :
        Node Type . . . . . . . . . . . . : Broadcast
        IP Routing Enabled. . . . . . . . : No
        WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Local Area Connection:

        Connection-specific DNS Suffix  . :
        Description . . . . . . . . . . . : Intel 21140 Based PCI Fast Ethernet
Adapter
        Physical Address. . . . . . . . . : 00-03-FF-85-D9-27
        DHCP Enabled. . . . . . . . . . . : Yes
        Autoconfiguration Enabled . . . . : Yes
        IP Address. . . . . . . . . . . . : 192.168.2.2
        Subnet Mask . . . . . . . . . . . : 255.255.255.0
        Default Gateway . . . . . . . . . :
        DHCP Server . . . . . . . . . . . : 192.168.2.1
        DNS Servers . . . . . . . . . . . :
        Lease Obtained. . . . . . . . . . : Monday, May 17, 2004 3:47:12 PM
        Lease Expires . . . . . . . . . . : Monday, May 17, 2004 4:02:12 PM

Note the times to the right of the "Lease Obtained" text and the "Lease Expires" text in this output.
Before the DHCP lease expires, use the Save state option in Virtual Server 2005 to save your virtual machine configuration.
After the DHCP lease expires, use the Restore From Saved State option in Virtual Server 2005 to start your virtual machine.
When your virtual machine is started, type ipconfig /all at a command prompt.
Note the "Lease Obtained" and "Lease Expires" times. When you compare these times with the times that you noted in step 3, you will see that the times have changed to reflect the new DHCP lease.

Note The DHCP lease is renewed a short time after the virtual machine is started.