When defining a proxy user in the DCS UMC and using windows (active directory) authentication – it does not work when defining “domain\user”. The setting cannot be parsed and the setting is therefore not send to the Security Virtual Appliance (SVA) hence the SVA will not use the setting and fails to download content updates.
You could notice an error when this setting has been set "domain\user" as the proxy user and then changing the SVA Config Base Policy - when saving the policy you'll see the error: "Unexpected System Error occurred. Please try again later, or contact service administrator"
A good way to see if the proxy user (and other proxy settings) is set as you would expect, is to generate the SVA Diagnostics Package (see TECH233614) and then look at the file: ContentManagerLUServerConfiguration.xml - this file has an entry for "UserName" and it won't be populated with "domain\user" as you would expect
Other errors that may be reported due to this issue are:
LiveUpdate session failed: LiveUpdate server selection failed
Content Update Server Selection Failed
Content Update Failed
Data Center Security Server 6.x (this issue was first reported in version 6.6).
The UMC fails to process the single back slash which in turn fails to save the configuration in the SVA configuration policy hence the configuration policy change doesn't end up at the SVA.
Workaround: When using "domain\\user" (double backslash) or "[email protected]" it does work.
A fix which would allow you to use just "domain\user" is targeted in DCS:S 6.7 MP1 due the beginning of February 2017 (subject to change).