Event ID 20174 — RRAS Multicast Scope Configuration

Applies To: Windows Server 2008 R2

A multicast scope is a named range of IP multicast addresses that is expressed with an IP address and mask. After multicast scopes are configured, you can use them to create scope-based multicast boundaries in the properties of an IP routing interface.

Routing and Remote Access can forward multicast traffic in limited network configurations. The primary use of Routing and Remote Access as a multicast router is to connect a subnet to a multicast-enabled intranet that contains routers running multicast routing protocols. To fully support efficient multicast forwarding on a multiple-router intranet, you must install multicast routers that run one or more multicast routing protocols.

Event Details

Product: Windows Operating System
ID: 20174
Source: RemoteAccess
Version: 6.1
Symbolic Name: ROUTERLOG_IP_POSSIBLE_LEAKY_SCOPE
Message: Possible leaky multicast local scope detected between this machine and: %1, since a boundary appears to exist for: %2, but not for the local scope. If this warning continues to occur, a problem likely exists.

Resolve

Configure multicast scope, boundaries, or heartbeat

To perform these procedures, you must have membership in Administrators, or you must have been delegated the appropriate authority.

Follow the procedures in the order in which they appear until the problem is resolved.

Configure multicast scopes

To configure multicast scopes:

A scope is a range of IP multicast addresses and is defined by specifying the address range as an IP address and mask. Multicast addresses in the range of 239.0.0.0 to 239.255.255.255 (239.0.0.0/8) are used to specify administrative scopes, as defined in RFC 2365. However, the range of 239.255.0.0/16 is defined as a local scope and cannot be divided further.

  1. Open Routing and Remote Access. Click Start, click Run, type rrasmgmt.msc, and then press ENTER.
  2. In the console tree, double-click the server name.
  3. Double-click IPv4, right-click General, and then click Properties.
  4. On the Multicast Scopes tab, click a multicast scope, and then click Edit.
  5. Review the settings, and then add or delete the scope, as appropriate.

Configure multicast boundaries

To configure multicast boundaries:

Multicast boundaries are administrative barriers that can be configured to limit how far routers can forward multicast traffic across a network. Without boundaries, a multicast router forwards all multicast traffic throughout the network. With boundaries, a multicast router forwards multicast traffic over a limited area of the network only.

  1. Open Routing and Remote Access. Click Start, click Run, type rrasmgmt.msc, and then press ENTER.
  2. In the console tree, double-click the server name.
  3. Double-click IPv4, and then click General.
  4. In the details pane, right-click the interface on which you want to configure multicast boundaries, and then click Properties.
  5. On the Multicast Boundaries tab, review the scope boundary settings.

Note:  Only scopes configured as multicast scopes are listed in Scope.

Configure multicast heartbeat

To configure multicast heartbeat:

Multicast heartbeat is the ability of a server running Routing and Remote Access to listen for a regular multicast notification to a specified group address to verify that IP multicast connectivity is available on the network. If the heartbeat is not received within a configured amount of time, the server running Routing and Remote Access sets the multicast heartbeat status of the configured interface to inactive.

  1. Open Routing and Remote Access. Click Start, click Run, type rrasmgmt.msc, and then press ENTER.
  2. In the console tree, double-click the server name.
  3. Double-click IPv4, and then click General.
  4. In the details pane, right-click the interface on which you want to configure multicast heartbeat, and then click Properties.
  5. On the Multicast Heartbeat tab, select the Enable multicast heartbeat detection check box.
  6. Add a multicast heartbeat group, and configure a quiet time.

Verify

To verify that multicast traffic is being forwarded to the multicast group address, on a receiving host, open a multicast-enabled application and verify streaming content is being received.

RRAS Multicast Scope Configuration

Routing and Remote Access Service Infrastructure