Consider the following scenario:
You have a server that is running Microsoft Forefront Unified Access Gateway (UAG) 2010 Service Pack 1 (SP1) Update 1.
You publish a web application through UAG 2010 by using the Other Web Application (portal host name) template.
When you browse to this web application, it sets a domain cookie. The domain that is specified for this cookie is the same as the domain of the UAG portal public host name, as in the following example:
UAG portal public host name: portal.contoso.com
Cookie domain, in the domain attribute of the Set-Cookie header: domain=.contoso.com
In this scenario, when UAG forwards the HTTP response of the back-end web server to the client, UAG changes the name of cookie by using host address translation (HAT).
To resolve this issue, install the rollup package that is described in the following Microsoft Knowledge Base article:
2647899 Rollup 1 for Forefront Unified Access Gateway (UAG) 2010 Service Pack 1 Update 1
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates