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Is anyone using Citrix to stream Windows 7 to workstations?

 

We’re running into some annoying hurdles in our pilot deployment.  We’re using Dell 745 workstations with the hard drives removed and booting off the network.  An Infoblox appliance is providing DNS/DHCP/TFTP services.

 

The device does a PXE boot and gets an IP address (1.1.1.1) and the boot file for the Citrix server from the Infoblox DHCP/TFTP server.  Once the Windows 7 OS is loaded, it issues a DHCP request and the DHCP server responds with a second IP address (1.1.1.2).

 

On our Infoblox DHCP server, I’ve set the PXE DHCP lease times to 5min.  However, if you run IPCONFIG on the Windows 7 system, you’ll see both IP addresses:

C:> ipconfig

IPv4 Address. . . . : 1.1.1.2 (Preferred)

IPv4 Address. . . . : 1.1.1.1 (Deprecated)

 

What’s odd is after the 5min PXE lease time, the Windows 7 OS still has the Deprecated IP address active.  While on the DHCP server, the lease status for that same IP address is “free” and it will attempt to offer that IP address again. (It fails to offer the IP address because the DHCP server issues a ping test before actually offering.  I don’t know how much of a time delay this introduces in offering a DHCP address to a device.  Wouldn’t think much.).

 

As a test, we assigned a fixed IP address to the MAC address of one of these workstations.  When it booted, the PXE boot and the Win7 OS used the same IP address.  So, we’re only using one IP address, but it’ll be additional overhead to manage if it changes networks.

 

So, the DHCP pool needs to be twice as large as the number of devices; however, we’d occasionally get the PXE-E51 error:  “ No DHCP or proxyDHCP offers were received”.   When we’d check the DHCP pool for that network, it would not be at 100% capacity.

 

I’m not sure where to start with this problem;

-          How/why is the Win 7 OS picking up the IP address assigned to the PXE boot image?  Is this a PXE or Win 7 problem?

-          PXE devices don’t send a “UID” to the DHCP server but Windows does; so, the DHCP server treats these as separate requests.  Is this a DHCP configuration problem since the workstation works when the same IP address is issued via DHCP based on the MAC address to both the PXE and Windows DHCP requests?  From what I’ve read, the DHCP server is supposed to respond with a different DHCPOffer if the “UID” is different in the DHCP request.

 

 

Any suggestions?

 

Thanks,

Andy

 

 

 

 

 

 

 

 

 

 

Andy Farrior

Director of Technology Services

Victoria College

2200 E Red River

Victoria, TX 77901

andy.farrior@victoriacollege.edu

o) 361.582.2547

f) 361.572.6492

 

********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.

Comments

Message from ryan.young@mastersny.org

Andy,
I manage our Wyse WSM servers which is at its core Citrix, I actually go to the citrix support site to fix my issues. We have not seen these issues at all but we have seen others along the way if you want to talk offline happy to share our config, now that we have the system up and running we could not be happier with it. Our user logon times are down to 13 seconds.

Best,
Ryan Young
Network / Systems Administrator
The Masters School
Dobbs Ferry, NY 10522
914-479-6671

From: "FARRIOR, Andy" <Andy.Farrior@VICTORIACOLLEGE.EDU>
Reply-To: The EDUCAUSE Network Management Constituent Group Listserv <NETMAN@LISTSERV.EDUCAUSE.EDU>
Date: Tue, 29 May 2012 11:18:10 -0500
To: <NETMAN@LISTSERV.EDUCAUSE.EDU>
Subject: [NETMAN] DHCP issues with PXE boot and Win7 OS streamed by Citrix

 

 

Is anyone using Citrix to stream Windows 7 to workstations?

 

We’re running into some annoying hurdles in our pilot deployment.  We’re using Dell 745 workstations with the hard drives removed and booting off the network.  An Infoblox appliance is providing DNS/DHCP/TFTP services.

 

The device does a PXE boot and gets an IP address (1.1.1.1) and the boot file for the Citrix server from the Infoblox DHCP/TFTP server.  Once the Windows 7 OS is loaded, it issues a DHCP request and the DHCP server responds with a second IP address (1.1.1.2).

 

On our Infoblox DHCP server, I’ve set the PXE DHCP lease times to 5min.  However, if you run IPCONFIG on the Windows 7 system, you’ll see both IP addresses:

C:> ipconfig

IPv4 Address. . . . : 1.1.1.2 (Preferred)

IPv4 Address. . . . : 1.1.1.1 (Deprecated)

 

What’s odd is after the 5min PXE lease time, the Windows 7 OS still has the Deprecated IP address active.  While on the DHCP server, the lease status for that same IP address is “free” and it will attempt to offer that IP address again. (It fails to offer the IP address because the DHCP server issues a ping test before actually offering.  I don’t know how much of a time delay this introduces in offering a DHCP address to a device.  Wouldn’t think much.).

 

As a test, we assigned a fixed IP address to the MAC address of one of these workstations.  When it booted, the PXE boot and the Win7 OS used the same IP address.  So, we’re only using one IP address, but it’ll be additional overhead to manage if it changes networks.

 

So, the DHCP pool needs to be twice as large as the number of devices; however, we’d occasionally get the PXE-E51 error:  “ No DHCP or proxyDHCP offers were received”.   When we’d check the DHCP pool for that network, it would not be at 100% capacity.

 

I’m not sure where to start with this problem;

-          How/why is the Win 7 OS picking up the IP address assigned to the PXE boot image?  Is this a PXE or Win 7 problem?

-          PXE devices don’t send a “UID” to the DHCP server but Windows does; so, the DHCP server treats these as separate requests.  Is this a DHCP configuration problem since the workstation works when the same IP address is issued via DHCP based on the MAC address to both the PXE and Windows DHCP requests?  From what I’ve read, the DHCP server is supposed to respond with a different DHCPOffer if the “UID” is different in the DHCP request.

 

 

Any suggestions?

 

Thanks,

Andy

 

 

 

 

 

 

 

 

 

 

Andy Farrior

Director of Technology Services

Victoria College

2200 E Red River

Victoria, TX 77901

andy.farrior@victoriacollege.edu

o) 361.582.2547

f) 361.572.6492

 

********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.

********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.

Message from mazenf@sfu.ca

Andy,

We had the same issue when PXE boot was used for imaging lab machines. Enabling the "one-lease-per-client" flag fixed this issue and a machine was capable of reserving only one IP address after this flag was enabled.

I hope this will help solve your issues.

**********************
   Mazen Fawwaz              
   Network Services      
   SFU, Burnaby
   Local: 778-782-7177
**********************


From: "Andy FARRIOR" <Andy.Farrior@VICTORIACOLLEGE.EDU>
To: NETMAN@listserv.educause.edu
Sent: Tuesday, May 29, 2012 9:18:10 AM
Subject: [NETMAN] DHCP issues with PXE boot and Win7 OS streamed by Citrix

 

 

Is anyone using Citrix to stream Windows 7 to workstations?

 

We’re running into some annoying hurdles in our pilot deployment.  We’re using Dell 745 workstations with the hard drives removed and booting off the network.  An Infoblox appliance is providing DNS/DHCP/TFTP services.

 

The device does a PXE boot and gets an IP address (1.1.1.1) and the boot file for the Citrix server from the Infoblox DHCP/TFTP server.  Once the Windows 7 OS is loaded, it issues a DHCP request and the DHCP server responds with a second IP address (1.1.1.2).

 

On our Infoblox DHCP server, I’ve set the PXE DHCP lease times to 5min.  However, if you run IPCONFIG on the Windows 7 system, you’ll see both IP addresses:

C:> ipconfig

IPv4 Address. . . . : 1.1.1.2 (Preferred)

IPv4 Address. . . . : 1.1.1.1 (Deprecated)

 

What’s odd is after the 5min PXE lease time, the Windows 7 OS still has the Deprecated IP address active.  While on the DHCP server, the lease status for that same IP address is “free” and it will attempt to offer that IP address again. (It fails to offer the IP address because the DHCP server issues a ping test before actually offering.  I don’t know how much of a time delay this introduces in offering a DHCP address to a device.  Wouldn’t think much.).

 

As a test, we assigned a fixed IP address to the MAC address of one of these workstations.  When it booted, the PXE boot and the Win7 OS used the same IP address.  So, we’re only using one IP address, but it’ll be additional overhead to manage if it changes networks.

 

So, the DHCP pool needs to be twice as large as the number of devices; however, we’d occasionally get the PXE-E51 error:  “ No DHCP or proxyDHCP offers were received”.   When we’d check the DHCP pool for that network, it would not be at 100% capacity.

 

I’m not sure where to start with this problem;

-          How/why is the Win 7 OS picking up the IP address assigned to the PXE boot image?  Is this a PXE or Win 7 problem?

-          PXE devices don’t send a “UID” to the DHCP server but Windows does; so, the DHCP server treats these as separate requests.  Is this a DHCP configuration problem since the workstation works when the same IP address is issued via DHCP based on the MAC address to both the PXE and Windows DHCP requests?  From what I’ve read, the DHCP server is supposed to respond with a different DHCPOffer if the “UID” is different in the DHCP request.

 

 

Any suggestions?

 

Thanks,

Andy

 

 

 

 

 

 

 

 

 

 

Andy Farrior

Director of Technology Services

Victoria College

2200 E Red River

Victoria, TX 77901

andy.farrior@victoriacollege.edu

o) 361.582.2547

f) 361.572.6492

 

********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.


********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.

Thanks!

 

The Infoblox appliance doesn’t appear to support that ISC DHCP configuration option as far as I can tell.

 

I’ll take it up with Infoblox.

 

Thanks again!

Andy

 

 

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