The VPN gateway <b>moon</b> controls the access to the hosts <b>alice</b> and
<b>venus</b> by means of two different Intermediate CAs. Access to
<b>alice</b> is granted to users presenting a certificate issued by the Research CA
whereas <b>venus</b> can only be reached with a certificate issued by the
Sales CA. The hosts <b>carol</b> and <b>dave</b> have certificates from
the Research CA and Sales CA, respectively. Initiator <b>moon</b> does not possess
copies of the Research and Sales CA certificates and must therefore request them from
the initiators <b>carol</b> and <b>dave</b>, respectively.