Rails keep adding _session_id in redirect..why?



Thanks to Russell N. I could redirect from one rails app to another
But during redirect… rails add an extra session key. Which is not in
my app at all. i.e my session name is _myapp_session_id and both of my
have the same session key as well as the session-domain set to

But during re-direct I get an extra session key “_session_id”… why do i
get this? what does this mean and where can i find a bit more
information about it. Any hint…/help…