The discovery mechanisms defined in this standard are expected to be used in many different network architectures. The following three architectures are Illustrated:

• Single MulticastSubnet;
• Multiple MulticastSubnets;
• No MulticastSubnet (or multiple MulticastSubnets with exactly one host each);

A MulticastSubnet is a network segment where all hosts on the segment can receive multicast packets from the other hosts on the segment. A physical LAN segment is typically a MulticastSubnet unless the administrator has specifically disabled multicast communication. In some cases multiple physical LAN segments can be connected as a single MulticastSubnet