IP Multicast Support
IP Multicast Support |
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Windows 2000 includes the mrinfo tool, which you can use to display the configuration of a multicast router. The configuration information can be used to aid in the troubleshooting of multicast forwarding and routing problems.
mrinfo queries a specified multicast router with a special message. The response to the query contains a version number, the list of interfaces and the neighbors on each interface, metrics, Time-to-Live (TTL) thresholds, and flags. mrinfo syntax includes:
mrinfo [ -d debug_level ] [ -r retry_count ] [ -t timeout_count ] multicast_router
Table 4.6 Mrinfo Command Options
| Option | Description |
|---|---|
| -d | Specifies the debug level. The default value is 0. When debug leve1 is set to 1, all packet warnings are displayed. When debug leve1 is set to 2, downed network notifications and all level 1 messages are displayed. When debug leve1 is set to 3, packet time-out notifications and all level 2 messages are displayed. |
| -r | Specifies the neighbor query retry limit. The default value is 3. |
| -t | Specifies how long in seconds mrinfo waits for a neighbor query reply. The default value is 4. |
Example of using mrinfo:
C:\>mrinfo 10.1.0.1
10.1.0.1(test1.ntdev.microsoft.com) [version 20.50,mtrace,snmp]:
10.1.0.1 -> 0.0.0.0 (local) [1/0/querier/leaf]
10.2.0.1 -> 10.2.0.2 (test2.ntdev.microsoft.com) [1/0]
10.2.0.1 -> 10.2.0.3 (test3.ntdev.microsoft.com) [1/0]
10.3.0.1 -> 0.0.0.0 (local) [1/0/querier/leaf]
In the previous example, mrinfo is run against a multicast router at 10.1.0.1. The first line shows the multicast router configuration: version number (for Windows 2000 routers, the version number reflects the build number of Windows 2000) and flags (mtrace and SNMP supported).
Each additional line displays the interfaces on the multicast router and the neighbors on each interface. Interfaces 10.1.0.1 and 10.3.0.1 have no neighbors. Interface 10.2.0.1 has two neighbors, 10.2.0.2 and 10.2.0.3. For each line, mrinfo displays the interface and neighbor, the domain name for the neighbor, the multicast routing metric, the TTL threshold, and flags indicating its role on the network such as the IGMP querier of the network (querier) or whether it has no neighbors (leaf).