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citrix farm subnetting, in the Network Performance / WAN Optimization forum on BrianMadden.com

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smortgage posted on Tue, May 5 2009 2:21 PM

Hello everyone,

 

I'm hoping someone has some helpful advice.

 

Currently, I have one very large citrix farm with 10 servers in this farm. Well the problem is I have all workstations and servers on one subnet. I want to reconfigure my subnets and have 5 servers on the new subnet and the other 5 servers on the old subnet.

 

What would be the best way to configure a farm with 2 diferent subnets?

 

Thanks in advance.

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Answered (Verified) Verified Answers

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Verified by smortgage

I'm not really understanding the point of doing things this way; however, you can have a single farm with half of your servers in one subnet and half of your servers in the other and use only one set of published apps.

First, establish your subnets and verify that there are no routing or DNS issues (A and PTR records).

Then, create two zones within Citrix (based on your subnets). Next, create a zone preference and failover policy to set the preferred zone for clients based on subnet (you'll need two policies). Finally, move servers to the correct zone and change the IP config for servers as needed. Once complete, users will be connected to servers in their preferred zone.

See this video tutorial for details: http://www.unitek.com/training/citrix/content/view/108/

Having said all that, I don't see much benefit in doing this for a LAN deployment. Typically, you would implement ZPF if you have a main data center and a DR data center with good IP connectivity between them and you desire automated failover.

Alan Osborne

President (MCSE, CCNA, VCP, CCA)

VCIT Consulting - Citrix/Terminal Services Remote Desktop Solutions for SMB

VCIT website My Blog

  • | Post Points: 40
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Verified by smortgage

If all of the servers in a particular zone are fully loaded, ZPF will redirect sessions to the secondary zone automatically.

This article summarizes the topic nicely (read carefully, twice):

http://grounding.co.za/blogs/trevor/archive/2008/02/28/to-share-or-not-to-share.aspx

Also, this read this article too:

http://www.msterminalservices.org/articles/Citrix-Presentation-Server-Load-Management-Part1.html

An important thing to keep in mind is that ZPF doesn't work for the PN client. You need to use the PN Agent (whatever that's called these days :-) or the web client. Finally, ZPF is only available with Enterprise edition.

Alan Osborne

President (MCSE, CCNA, VCP, CCA)

VCIT Consulting - Citrix/Terminal Services Remote Desktop Solutions for SMB

VCIT website My Blog

  • | Post Points: 40

All Replies

Top 25 Contributor
Points 7,839

If you have 2 nics on each server, it would be to your advantage to have one subnet on each, but if not, it shouldn't matter what subnet the servers are on if you want to split them in half.

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Will Citrix be smart enough to send requests to the servers on subnet A if the requestor is on subnet A and same with subnet B or will Citrix send traffic over both subnets??

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Points 14,534

How are you going to route between the subnets, not through the servers I hope!

--Emil

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Top 10 Contributor
Points 24,510

What is your reasoning for creating two subnets in the first place? If the idea is to reduce your collision domain and cut down on broadcast traffic, you would be better off carving out a seperate subnet for your entire Citrix farm (and other back-end servers) and use your existing subnet for workstations and printers only, rather than splitting up your farm among subnets.

Also, if your concern is that you are running out of addresses on your existing subnet, with CIDR addressing you can simply change your subnet mask by 1 bit to double the size of your existing subnet without having to create a second subnet.

Alan Osborne

President (MCSE, CCNA, VCP, CCA)

VCIT Consulting - Citrix/Terminal Services Remote Desktop Solutions for SMB

VCIT website My Blog

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Points 250

Thanks Allen for you reply.

Yes, thats correct we would like to reduce our cloision domain and cut down on broadcast traffic.

Each subnet will have its own Citrix metaframe server. Subnet A will have 5 citrix server and subnet B will its own Citrix server. Is it possible to have 1 farm (10 citrix servers) on 2 different subnets and on each subnet the workstations will be only using resources from their corresponding Citrix servers.

ie.) Workstations on subnet A will communicate to the Citrix servers on only subnet A?

Or will have to create 2 farms for each subnet?

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Points 2,460

You would have to publish 2 different applications to do what you want. App A for people on subnet A and App B for subnet B.

This is NOT the recommended way of configuring an environment. Put your servers on one subnet and your users on different subnets. If you need more subnets for your users, so be it, it will have no impact on your server farm.

  • | Post Points: 5
Top 10 Contributor
Points 24,510
Verified by smortgage

I'm not really understanding the point of doing things this way; however, you can have a single farm with half of your servers in one subnet and half of your servers in the other and use only one set of published apps.

First, establish your subnets and verify that there are no routing or DNS issues (A and PTR records).

Then, create two zones within Citrix (based on your subnets). Next, create a zone preference and failover policy to set the preferred zone for clients based on subnet (you'll need two policies). Finally, move servers to the correct zone and change the IP config for servers as needed. Once complete, users will be connected to servers in their preferred zone.

See this video tutorial for details: http://www.unitek.com/training/citrix/content/view/108/

Having said all that, I don't see much benefit in doing this for a LAN deployment. Typically, you would implement ZPF if you have a main data center and a DR data center with good IP connectivity between them and you desire automated failover.

Alan Osborne

President (MCSE, CCNA, VCP, CCA)

VCIT Consulting - Citrix/Terminal Services Remote Desktop Solutions for SMB

VCIT website My Blog

  • | Post Points: 40
Not Ranked
Points 250

Thanks Alan and everyone else for the responses!  Alan, yYou are correct in that this is all being done for DR purposes.  Basically here's the setup;

 

2 Buildings (A and B)

Connected through a BridgeWave High Speed Wireless link

 

Currently all the physical Citrix Servers are located in A

Both sites were on the same subnet and all traffic was going through the one bridgewave link.

 

For DR reasons we broke site A into its own subnet and site B into another (we finished this a few hours ago), the vision is that we will set up DR in such a way that if A goes down B will be able to take over.  However, for everyday work I want to minimize traffic through the wireless connection so we are setting up Citrix Servers in B now and I want to make sure that when a user in B accesses an application, it hits the B Citrix Servers rather than going over the Bridgewave and hitting the A Servers.  Users from site A will still obviously go through site A Citrix Servers.  Hope that make a bit more sense.  I'm not doing this in one building, it's more to seperate the two buildings and take away the wireless bridgewave from being the single point of failure.  If A goes down B still needs to be functional, and vice versa with B. Basically building B was set up in record time and the previous Admin didn't have time to get it up correctly, we're trying to fix that now.

With that new information, is there something else we're missing here?

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Just watched the video and that's exactly what I want to happen.

 

Is there a way to put threshholds on the two sites?  So if site A's Server's are running too hot then it will send the user to site B's Servers instead?

  • | Post Points: 20
Top 10 Contributor
Points 24,510
Verified by smortgage

If all of the servers in a particular zone are fully loaded, ZPF will redirect sessions to the secondary zone automatically.

This article summarizes the topic nicely (read carefully, twice):

http://grounding.co.za/blogs/trevor/archive/2008/02/28/to-share-or-not-to-share.aspx

Also, this read this article too:

http://www.msterminalservices.org/articles/Citrix-Presentation-Server-Load-Management-Part1.html

An important thing to keep in mind is that ZPF doesn't work for the PN client. You need to use the PN Agent (whatever that's called these days :-) or the web client. Finally, ZPF is only available with Enterprise edition.

Alan Osborne

President (MCSE, CCNA, VCP, CCA)

VCIT Consulting - Citrix/Terminal Services Remote Desktop Solutions for SMB

VCIT website My Blog

  • | Post Points: 40
Not Ranked
Points 250

perfect!  Good thing our new desktop deployment got rid of program neighborhood and replaced it with pnagent :)  Thanks again!!

  • | Post Points: 5
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