Per default configuration,osquery in a windows asset checks, if it can reach to uptycs cloud; before doing an Enrollment request.

If it is able to connect, it will continue without using any proxy. If above connection attempt fails,

1) Then osquery tries to get information from operating system. In case of windows, a pac file setting is given preference to a manually configured proxy server setting.It then uses the configured proxy (or list of proxies) to test connectivity to the cloud  and proceeds with enrollment request etc. 

2) If connecting via OS configured proxy fails or if no OS-configured proxy is found, osquery reads the proxy_hostname flag. The flag may contain a single proxy or a list of proxies (separated by a comma but no space). Osquery tries to use the specified proxy or each proxy from the list to test connectivity to the cloud.  

3) The first successful connection to the cloud via a proxy selected using above two steps is considered  as the best proxy and is locally  cached,stored into the osquery database for further subsequent connections to the cloud. This cache is used unless a connection  to  the cloud fails, in which case the above steps are re-executed to find a new best proxy server to connect to the cloud.  

4) Password protected proxies are not supported. 

NOTE: proxy_hostname flag is not packaged by default in the  osquery msi file, but it is available in  GUI under Configuration >> Flag Profiles >> Misc( in flags listing) >> proxy_hostname.  Upon setting this value as desired, asset will get updated with this configuration during next config update. But, note that asset will need to connect via regular network link to download this config.  If you will need a MSI package pre-updated with list of proxy entries, Please contact uptycs support - via support.uptycs.com portal.