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DFS-R Design

So, I am in the process of deploying a simple DFS-R infrastructure.  I have about 70+ servers in just as many remote offices that act as File & Print servers but, they also will double as App-V streaming servers.  I want to use DFS-R to keep the App-V content share consistent on each server.  Now I know that DFS-R uses RPC to replicate the data to each server.

My road blocks are: We will have a mixed bag of '03 R2 and '08 R2 systems which use different RPC ports.  Another is: our network security team will not allow these RPC random ports.  Rather than just isolate DFS-R replication to a single port as outlined in:  http://support.microsoft.com/kb/319553/en-us.  I was thinking I can accomplish both issues by limiting all RPC coming from the server on a port range of 300 (Example: 5000-5300)  I chose 300 because the minimum port range for Windows server '08 is 255 and I wanted a round number:).

I was going to follow the following articles:

Windows Server 2003: http://support.microsoft.com/kb/154596

Windows Server 2008: http://blogs.technet.com/b/askds/archive/2007/08/24/dynamic-client-ports-in-windows-server-2008-and-windows-vista-or-how-i-learned-to-stop-worrying-and-love-the-iana.aspx

I was hoping that someone could provide feedback or flaws.

Thanks,
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JTOCCO
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JTOCCO
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PberSolutions ArchitectCommented:
Ugh, I feel your pain.  Anything that I deploy usually has to deal with a firewall and my network guys are very stingy when it comes to what I can do.  
The Microsoft article 319553 will work.  I've used this before through the firewalls as well.    Normally you would need high ports to a destination of 135 and then it will negotiate a random high port, but hardcoding it as per the 319553 works.  
I have also limited the RPC ports ranges as you also are considering.  The one thing to keep in mind is that limiting your RPC ports can have some downside if your servers are really busy because they may run out of ports.
My network guys also like the limited range as well.  If I can give them a port rule small source port range, they are usually much happier.
 
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JTOCCOAuthor Commented:
Thanks for the info!

So, as far as restricting RPC as a whole from the server.  Would you suggest increasing the amount of ports to say 1000 from 300?

Also, have you run DFSR in an enviornment this way instead of using microsoft's KB319553.
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PberSolutions ArchitectCommented:
You can monitor it.  Low usage servers you might be fine with 100 ports, Servers with lots of users or applications such as SQL, you may deplete the available RPC ports quickly.  You'll get RPC errors if you run out.
You can also sniff with netmon and watch the RPC ports.  You'll see the source ports go up from your defined range.  They eventually get re-used as connections come up and drop.  Experiment with 300 and see how it goes.
As far as DFSR, that is generally how I've done it not restricting to a specific port, but to use a constricted RPC range.  Works fine.
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JTOCCOAuthor Commented:
I appreciate the input!
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PberSolutions ArchitectCommented:
Glad to help.
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