Where are updates synchronized from in WSUS?

go to start menu in administrative tools category you can find Windows server Update Services (WSUS )

or go to control panel and select administrative tools and open the WSUS

here I have opened it from recent programs

after open It navigate to the synchronization section

right click on synchronization and select synchronize now ( I assume that you have configured update source  and proxy server  settings )

synchronize will start

you can view the synchronize progress during the process

leave it while, it will take some time.it depends on your number of updates, connection speed blah blah

soon after it finished you can see the sync  details

for more details you can click on the synchronization that you want to see the details report and right click after select synchronization report

or you can select synchronization and go to action menu and select synchronization Report. be patient it will take some time to generate the synchronization report

view of a detailed report generated

from the synchronization report you can  view available new update one be one.

in synchronizations you will able to see the number of synchronizations which have carried out no matter they have successful or not

If you are having problems with the synchronization of updates, look at the some of the following rough patches for some assistance:

■ Check proxy server settings from the WSUS console. If your proxy server supports authentication, make sure you have the correct user name, password, and domain. Also be aware that by using basic authentication, you are sending your credential information in plaintext over the wire.

■ Verify the name of the upstream WSUS server. This must be spelled exactly. If you suspect other communication or name resolution problems, try pinging the upstream server from the downstream WSUS server that is having the problems. Just make sure when pinging that you are using the same naming convention used in the WSUS console.

■ Check the update storage options you have configured. If you are using a chain of WSUS servers together in a hierarchy, the entire hierarchy must use the same update storage option; otherwise, the synchronizations fail. Consequently, if the upstream server stores content locally, each of the downstream WSUS servers must store content locally as well. Make sure that each WSUS server in the chain uses the same option for update storage.

■ Verify permissions on the update storage directory. Check to see that the folder where you download update files has "Read" permissions for NETWORK SERVICE and for Authenticated Users, whether or not the server you download the update files to is an upstream or downstream machine. The directory is c:\Update Services\UScontent. (See Figure 11.1)

Figure 11.1 Verifying Permissions

Make sure the upstream WSUS server actually has updates available. There are a couple of scenarios where there might be a mismatch in update availability. In the first scenario, an upstream server is reinstalled; thus, the list of classifications and updates that the administrator selects changes. A future synchronization will fail when a downstream server asks for updates that do not exist on the upstream server. In the second scenario, you might configure a downstream server to retrieve updates from a different upstream server with another set of products and classifications selected. Either of these scenarios would result in mismatched update numbers.There are a few ways to fix this: (1.) Specify the missing updates on the upstream server and then synchronize from the update source; (2.) make sure you cancel the updates that are not on the upstream server and decline the old updates on the downstream server; or (3.) if the missing updates are available on the upstream server, then the error is transient, and things will eventually fix themselves.

Try restarting the Background Intelligent Transfer Service (BITS) service.You can do this from the Services Microsoft Management Console (MMC) under Administrative Tools in the Start menu (see Figure 11.2).

Figure 11.2 Restarting BITS

Figure 11.2 Restarting BITS

■ Try restarting the WSUS service. Again, this can be done from the Services MMC console under Administrative Tools in the Start menu. Try to synchronize again.

■ Make sure your environment supports Hypertext Transfer Protocol (HTTP) v1.1. If you are receiving errors regarding the Range protocol being unsupported, you must change a setting from the command line. Stop the WSUS service and issue the following command: "%programfiles%\Update Services\tools\osql\osql.exe" -S SQL_InstanceName -E -b -n -Q "USE SUSDB update tbConfigurationC set

BitsDownloadPriorityForeground=1". Replace the SQL_instanceName as appropriate. Then, restart the WSUS service and perform the synchronization again.

Some Independent Advice_

We have found that a lot of WSUS problems are solved by the timeless Windows fix: reboot. If you do not want to take down the whole machine, just restart the BITS service and the WSUS service and try again.

Where does WSUS pull updates from?

Where are WSUS updates stored?