Comment Feed for Branch Cache in Windows 7 (Media on TechNet Edge)

Re: Re: Branch Cache in Windows 7

Yaşar Tuna Zorlu — Fri, 04 Sep 2009 23:30:30 GMT

Well i found that presentation on a turkish site.

If it is allowed here it is : http://mshowto.org/images/articleimages/ones/MSHowto_Win7_Sunum.zip (English presentation)

Re: Re: Re: Branch Cache in Windows 7

Yaşar Tuna Zorlu — Fri, 04 Sep 2009 23:23:07 GMT

Hmmm.

Group Policy is a litle bit complex. There are lots of entries; but i really can't choose "the one"

If you tell us what to do, i ll be very grateful (at least we can test it on our machines)

Thanks by the way...

Update:

Well i found that info from microsoft itself

Client : http://technet.microsoft.com/en-us/library/dd637820(WS.10).aspx

Server : http://technet.microsoft.com/en-us/library/dd637785(WS.10).aspx

Adopters Guide : http://technet.microsoft.com/en-us/library/dd637762.aspx

Hope that helps. (a little bit confusing)

Re: Re: Branch Cache in Windows 7

Adam Bomb — Fri, 04 Sep 2009 17:53:04 GMT

this is a feature you need to enable. It needs to be enabled on your Windows 2008 Server R2 machines, and then has to be enabled on your Win7 clients - most customers will do this via Group Policy. The feature isn't available for home group machines - it requires Pro/Enterprise/Ultimate edtions.

hope that helps!

Re: Branch Cache in Windows 7

Yaşar Tuna Zorlu — Fri, 04 Sep 2009 15:46:45 GMT

Well maybe can one of you answer my question.

As we saw the three lappy over there, one meant to be the server and the others acting like the office mates and one downloads a data from the source and then the other downloads the same data but in seconds.

But let u clear our minds.

First Question:

Is that feature enabled as default or we have to make it enabled.

Second Question:

Do we have to make each two laptop to be in the same home group that windows 7 serves?

I appreciate your answer.

Indeed it is a very good presentation. Thanks Adam and Devrim. ;)

Re: Branch Cache in Windows 7

John Wilkins — Sat, 30 May 2009 12:00:53 GMT

Can we download a copy of the powerpoint presentation that Devrim used during her discussion?

Re: Branch Cache in Windows 7

cccsec — Thu, 28 May 2009 13:54:03 GMT

Nice feature - one more good reason to migration Clients and Servers to the upcoming releases. However, what about write cache, like:

(1) branch office client A requests file from headquarter server

(2) another branch office client B reads the file from client A

(3) client B makes changes to the file

How is the file written back to the headquarter server (like Sharepoint or SMB) ?

(4a) Client B writes the full file back to the headquarter server

(4b) Client B writes only the changed blocks back to the headquarter server

However, reading should already lighten the bandwidth load significantly - so congrats for this feature!!

cccsec

Re: Branch Cache in Windows 7

chengajun — Wed, 08 Apr 2009 02:54:55 GMT

I have configured a file server which can run branch cache successfully by following the <BranchCache Early Adopter's Guide>, how ever the IIS dosen't work.
how can i branchCache IIS?

Re: Branch Cache in Windows 7

ajith E — Mon, 16 Mar 2009 14:09:00 GMT

Does it cache all HTTP content or only the ones with the pre-requisite "HTTP:" headers.

For how long does it cache HTTPS & CIFS SMB content?

Re: Branch Cache in Windows 7

ates — Fri, 06 Mar 2009 07:40:43 GMT

Teşekkürler Devrim :)

Re: Branch Cache in Windows 7

Derek Schauland — Tue, 24 Feb 2009 20:39:37 GMT

How does the branch caching feature deal with possible cache poisoning as has been seen when DNS is cached?

Re: Branch Cache in Windows 7

David Stafford — Wed, 04 Feb 2009 15:32:41 GMT

If sourced from peers (vs. hosted cache) - will I be serviced from just one or multiple caches ? (Torrent-esque)

Subsequently, can rate-limiting be applied via GPO to minimize potential impact to other upload sensitive apps. (Like a soft-phone client)

Re: Branch Cache in Windows 7

Kerry Brown — Thu, 29 Jan 2009 16:26:16 GMT

It appears that the BranchCache service takes over port 80 which interfers with using Apache on a workstation. What are the implications of disabling the BranchCache service on a workstation in order to free up port 80?

Re: Re: Re: Branch Cache in Windows 7

Goran Topalovic — Mon, 26 Jan 2009 20:01:18 GMT

This new feature reminded me on ISA Branch office scenario, and that is why I thought it was based on ISA Server.

"Basically, a client will only read content from a peer (or hosted cache) which matches the content hashes the client retrieved from the original content server."

This makes AV software irrelevant on the client machine in the distributed scenario, and this answers my question completely.

Thank you.

Re: Re: Branch Cache in Windows 7

efla — Mon, 26 Jan 2009 17:45:57 GMT

Windows BranchCache will not be available on Windows Server 2008. It will be available on Windows Server 2008 R2 and Windows 7. BranchCache is a brand new feature and is not based on any feature in ISA server.

In a distributed scenario or in a hosted cache scenario the defense against malicious content is the same. Basically, a client will only read content from a peer (or hosted cache) which matches the content hashes the client retrieved from the original content server.

Example:
----
Client1 wants to access http:\\headquarters\example.foo. Client1's HTTP stack resolves headquarters and sends it an HTTP GET for example.foo.

The headquarters server responds with BranchCache content information for example.foo (essentially hashes used to validate that some data are in fact part of the original content).

Client1 searches on the LAN for peers who have any part of the content (content is identified by a hash derived from the content itself so there is no ambiguity about which version of a file is being requested). Client0 responds that it has the content. Unfortunately, Client0 somehow ended up with a copy of example.foo which is infected with malware.

Client1 downloads example.foo from Client0 in small chunks. Each chunk is hashed (using SHA-256 or higher) and compared to the hashes download in the content information from the headquarters server. If any chunk's hash fails to match the hash Client1 got from headquarters then Client1 stops communicating with Client0 and tries to get the content from other peers. Because Client0's copy of example.foo is infected it must not match the clean copy on the headquarters server so some part of it will fail to match the hashes Client1 retrieved from headquarters (either that or headquarters had an infected copy to start with, which BranchCache can't defend against). A process which is using BranchCache to retrieve a file will not see any content chunks whose hashes do not match the hashes retrieved from the server.
----

Regarding malware scanning software, use of any software which tries to detect malware by comparing files to a database of examples of known malware is questionable for defending against new threats. Malware authors have access to the malware scanning engine. All the malware author needs to do is massage the format of the malware until the malware detector fails to detect it. The malware detector must respond by identifying the new malware by some other means and shipping an update to the malware detector. The malware authors always have the advantage.

Re: Branch Cache in Windows 7

Goran Topalovic — Mon, 26 Jan 2009 05:17:03 GMT

It is nice to see that great features from great products, such as ISA server, are embedded in desktop and server OS. I presume that this will not be available in Vista and Windows 2008.
I would like to know what happens if in distributed scenario, when the client that has file which is infected, and other "clean" client is asking for that file, what would happen. Maybe this would be another way to spread the malware through the network. In addition, yes I know that Defender is free, but its usability is questionable, from my experience©.