The roadwarriors <b>carol</b> and <b>dave</b> set up a connection each to gateway <b>moon</b>
using EAP-TTLS authentication only with the gateway presenting a server certificate and
the clients doing EAP-MD5 password-based authentication.
<p/>
In a next step the <b>RFC 7171 PT-EAP</b> transport protocol is used within the EAP-TTLS
tunnel to determine the state of <b>carol</b>'s and <b>dave</b>'s operating system via the
<b>TNCCS 2.0 </b> client-server interface compliant with <b>RFC 5793 PB-TNC</b>. The OS IMC
and OS IMV pair is using the <b>IF-M 1.0</b> measurement protocol defined by <b>RFC 5792 PA-TNC</b>
to exchange PA-TNC attributes.
<p/>
<b>carol</b> sends information on her operating system consisting of the PA-TNC attributes
<em>Product Information</em>, <em>String Version</em>, and <em>Device ID</em> up-front
to the Attestation IMV, whereas <b>dave</b> must be prompted by the IMV to do so via an
<em>Attribute Request</em> PA-TNC attribute. <b>dave</b> is instructed to do a reference
measurement on all files in the <b>/usr/sbin</b> directory. <b>carol</b> is then prompted to
measure a couple of individual files and the files in the <b>/usr/sbin</b> directory as
well as to get metadata on the <b>/etc/tnc_confg</b> configuration file.
<p/>
Since the Attestation IMV negotiates a Diffie-Hellman group for TPM-based measurements,
the mandatory default being <b>ecp256</b>, with the strongswan.conf option
<b>mandatory_dh_groups = no</b> no ECC support is required.
<p>
<b>carol</b> passes the health test and <b>dave</b> fails because IP forwarding is
enabled. Based on these assessments which are communicated to the IMCs using the
<em>Assessment Result</em> PA-TNC attribute, the clients are connected by gateway <b>moon</b>
to the "rw-allow" and "rw-isolate" subnets, respectively.
</p>
