How to replace a missing Http header bu using F5 ?

Maxime -

It is possible. You will need to use a sideband connection to query the LDAP. Then replace the header as needed.

This will get you started with the side band connection LINK

This is a fairly intensive iRule, and if you are new at it, it may be frustrating. The check for the null header, and the header insertion is the easy part, the sideband stuff is not for the faint of heart.

If you don't have the kind of time or bandwidth needed to accomplish this, I know F5 Pro Services does it somewhat regularly.

Hope This Helps, Jeff