HeaderVar Not Showing Up Or Wrong Value
Have you ever had some header variables show up and not others?
You think to yourself, ” I must have a different authorization rules or expression that is being invoked and returning different headers.” But when you go check in the Access Tester it is the rule that you are thinking of that is being tripped and there are no different actions on the authorization expression.
This is a peculiar problem that sometimes occurs and as near as I can tell this is what causes the problem. Why this seems to be the case, I have no idea. The problem occurs when one header variable name is completely encompassed in anothers name. For example the variable MYNAME is fully encompassed by MYNAMEPREFIX. If MYNAME comes first (or is it the other way around?) in the header variable list then strange things will happen and the results viewable in the header will not be what you expect .
There seem to be two resolutions to this: (1) ensure the longer one shows up in the list first OR (2) given them completely dissimilar names. I personally think that option 2 is the way to go. Option 1 can be fraught with more heartache if the orders get reversed down the road in a different environment.
I have only witnessed this behaviour on COREid 7 WebGate for IIS 5/6 . It has been reproduced across separate installations. I have not tried to reproduce it elsewhere yet.