Default Login page to external login in domain separated instance

[Rithika1]

I have this requirement to default external login when user tries to fetch and login into service portal. My instance is domain separated , can anyone suggest a way to configure this without effecting other domain.

[Maik Skoddow]

You will need the Multi-SSO plugin of ServiceNow (https://docs.servicenow.com/bundle/washingtondc-platform-security/page/integrate/single-sign-on/conc...) 

The differentiation for the external login is based on the field "SSO source" in the sys_user table which contains the Sys ID of the respective SSO configuration. That means it is not differentiated by any domain.