If you publish multiple Web Applications through ISA Server you might have experienced that users are asked to re-validate when one published site is linking to another published site even thought the sites are using the same user repository to validate users.
Fortunately, there is an easy fix for that: ISA Server SSO
ISA SSO offers Single Sign-on between site in the same DNS domain, provided:
- the published sites share the same Web Listener
- the same port number and protocol is used
- the users must be validated in the same user repository using the same authentication method
This means that SSO between http://sales.contoso.com and http://marketing.contoso.com is possible but SSO between http://sales.contoso.com and http://sales.contoso.org is not.
ISA SSO is enabled on the SSO tab in the Web Listener.
More information: