Problem: Unable to authenticate against SLIP Basic Auth.
Affects: All users accessing secured services at https://services.slip.wa.gov.au/arcgis/services
Description: Less than 1% of secured requests to SLIP are either being denied, or receiving a socket time out error.
Workaround: Where using SLIP services via an interactive map avoid void embedding basic auth for every request made. Instead, do an initial request to login and rely on cookies to pass the login token back for future requests.
For more information refer to "How does data.wa.gov.au’s authentication system work?".