By the way: browsing the internet works.

Only downloads seems to be the problem. But not on all websites.
Download begins and some kbytes are transfered... then speed decreases and download halts.

LiveUpdate will timeout after a short while.

increase the timeout value as per this document

http://www.symantec.com/business/support/index?page=content&id=TECH188847

Had there been issues previously or did it work before?

Hi Rafeeq,

tried it now. Did not help.

Hi _Brian,

no, not that im have been aware of.

It's a server at a customer's site.

increasing the timeout for LU did not solve the issue

Hello Thomas,

open control pannel, select liveupdate, make it interactive

click on start - run - luall.exe

select only small components , try to download , it might show you the actual error code, 

post the lue.log , we will see why its not downloading

http://www.symantec.com/business/support/index?page=content&id=TECH168602

Hi Rafeeq,

it seems that I am having a general issue with the server. I am not sure how to trouble shoot it...

IE and Chrome downloads behave in similar way when downloading. I have tested download from Win7 workstations that are using same DNS and default gateway / firewall. The workstations does not have the issue.

Here's a screen shot of LUALL where I selected just a small package.
It hangs after a few KB... The lue.log does not show an error because I cancel it before it actually just reach a timeout

No error message. 

Really strange - have never seen anyting like it.

Users reports that network connection speed to and from the server is good. Internet access also performing a normal.

The SEPM content has not been updated since may 26.

try uninstall / reinstall of liveupdate once

How to Uninstall and Reinstall LiveUpdate on SEPM 12.1 (Enterprise Edition or Small Business Edition)

http://www.symantec.com/business/support/index?page=content&id=TECH171060

I have finally resolved the issue.

Never heard about having too much RAM could get you into trouble.......

Stumbled over the following kb article:
http://support.microsoft.com/kb/2634907/en-us

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TCP/IP packets that are received out of sequence are discarded in Windows 7 or in Windows Server 2008 R2

Assume that you install Windows 7 or Windows Server 2008 R2 Standard Edition on a computer that has more than 32 gigabytes (GB) of RAM. When the computer tries to communicate with another computer by using the TCP/IP protocol, all the TCP/IP packets that are received out of sequence are discarded. Additionally, the fragmented packets cannot be reassembled.

Note This issue causes retransmission overhead. Additionally, all network-related activity is affected. For example, when you try to perform a file transfer or perform a remote access session on the computer, network performance is affected by the retransmission overhead.
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The solution was installing the hotfix provided by Microsoft in the kb.

The server had 36 GB RAM. But of cause only 32 GB can be utilized on Windows Server 2008 R2 Standard (SBS 2011)