3.7.5.2 Receiving Message #2

On receipt of message #2, the host MUST check for the presence of the "MS-Negotiation Discovery Capable" vendor ID payload (for details, see section 3.7.4.1) and set the Negotiation Discovery Supported flag for the corresponding MMSAD entry.

Messages #3 and #4 MUST be constructed and processed as specified in [RFC2409] section 5.