Multicast Routing Monitor (MRM)

MRM

Multicast Routing Monitor (MRM) facilitates automated fault detection in a large multicast routing infrastructure. MRM is designed to alert a network administrator of multicast routing problems near to real-time.
MRM has two components: MRM tester and MRM manager. MRM tester is a sender or receiver.
MRM is available in Cisco IOS Software Release 12.0(5)T and later. Only the MRM testers and managers need to be running the MRM-supported Cisco IOS version.

Test Sender Configuration
interface Ethernet0 ip mrm test-sender

Test Receiver Configuration
interface Ethernet0 ip mrm test-receiver

Test Manager Configuration
ip mrm manager test1 manager e0 group 239.1.1.1 senders 1 receivers 2 sender-list 1 access-list 1 permit 10.1.1.2 access-list 2 permit 10.1.4.2

Output from the show ip mrm manager command on Test Manager is shown here:

Test_Manager# show ip mrm manager 
   Manager:test1/10.1.2.2 is not running 
     Beacon interval/holdtime/ttl:60/86400/32 
     Group:239.1.1.1, UDP port test-packet/status-report:16384/65535 
     Test sender: 
       10.1.1.2 
     Test receiver: 
       10.1.4.2

Start the test with the command shown here. The test manager sends control messages to the test sender and the test receiver as configured in the test parameters. The test receiver joins the group and monitors test packets sent from the test sender.

Test_Manager# mrm start test1 
 *Feb  4 10:29:51.798: IP MRM test test1 starts ......  
Test_Manager#

In order to display a status report for the test manager, enter this command:

Test_Manager# show ip mrm status  

IP MRM status report cache:  
Timestamp        Manager          Test Receiver   Pkt Loss/Dup (%)       Ehsr  
*Feb  4 14:12:46 10.1.2.2         10.1.4.2        1            (4%)      29  
*Feb  4 18:29:54 10.1.2.2         10.1.4.2        1            (4%)      15  
Test_Manager#

The output shows that the receiver sent two status reports (one line each) at a given time stamp. Each report contains one packet loss during the interval window (default of one second). The "Ehsr" value shows the estimated next sequence number value from the test sender. If the test receiver sees duplicate packets, it shows a negative number in the "Pkt Loss/Dup" column.
In order to stop the test, enter this command:

Test_Manager# mrm stop test1 
*Feb  4 10:30:12.018: IP MRM test test1 stops  
Test_Manager# 

While running the test, the MRM sender starts sending RTP packets to the configured group address at the default interval of 200 ms. The receiver monitors (expects) the same packets at the same default interval. If the receiver detects a packet loss in the default window interval of five seconds, it sends a report to the MRM manager. You can display the status report from the receiver if you issue the show ip mrm status command on the manager.