Multicasting is the sending of network traffic to a group of endpointsdestination hosts. Only those members in the group of endpoints hosts that are listening for the multicast traffic (the multicast group) process the multicast traffic. All other nodes hosts ignore the multicast traffic.

Multicast scopes are supported by using Multicast Address Dynamic Client Allocation Protocol (MADCAP), a protocol for performing multicast address allocation. The MADCAP protocol describes how multicast address allocation or MADCAP servers can dynamically provide IP addresses to other computers (MADCAP clients) on your network.

Typically, a MADCAP server is also a multicast server (MCS) used to support IP multicasting. An MCS manages the shared or group use of the allocated multicast IP address and streams data traffic to members that share the use of the specified group address.

After an MCS is configured and allocated a group address to use, any multicast clients that have registered their membership with the MCS can receive streams sent to this address. By registering with the MCS, clients can participate efficiently in the stream process, such as for real-time video or audio network transmissions. The MCS also manages the multicast group list, updating its membership and status so that multicast traffic is received by all current members.

You can use this procedure to create a multicast scope.

Membership in the Administrators or DHCP Administrators group is the minimum required to complete this procedure.

To create a multicast scope
  1. Open the DHCP Microsoft Management Console (MMC) snap-in.

  2. In the console tree, click the DHCP server you want to configure.

  3. On the Action menu, click New Multicast Scope.

  4. Follow the instructions in the New Multicast Scope Wizard.

Additional Resources

For a list of Help topics providing related information, see Configuring DHCP Server Role Settings.

For updated detailed IT pro information about DHCP, see the Windows Server 2008 documentation on the Microsoft TechNet Web site.