I have a load generator that appends a ASP.NET_SessionId to the Cookie when making a Soap test call from Machine A to Machine B.

Cookie: ASP.NET_SessionId=gf0ouay24sdneiuicpiggn45;

However, when I'm running the soap test hitting my local server it doesn't have an ASP.NET_Session variable in the cookie.

Why is this happening?

UPDATE:

I'm getting this issue now on the server:

Forms authentication failed for the request. Reason: The ticket supplied was invalid.

I've followed this: http://msmvps.com/blogs/omar/archive/2006/08/20/108307.aspx

But to no avail.