The MRM is a great tool to use on multicast networks and on any routers therein. Three pieces are necessary to perform a "live" multicast test: a test sender (multicast source), test receiver (multicast receiver), and test manager.
The network in Figure 3-14 shows how an MRM test can be laid out.
Figure 3-14. Multicast Testing
Figure 3-14. Multicast Testing
The number of multicast routers within the Multicast Forwarding Network is irrelevant. Place thc test sender and test receiver appropriately to test and troubleshoot different parts of thc network.
phe tev- sen der, ou itc Et heinetO inherface, will use the ip mrm test-sender interface Command. hike wnse, the te5t receive., on its EthernetO intprface, wi- coe the -p mrm testtf -eceiveg interface c op-mand.
The best manage r ws| requ ire more configuratio it steps. First, nqu rcdst con-igure acce ss lists delineat1 hk the sen deifc and re ceivers on a netwFrkl A standard access 1 i deMneates specific hostPi ■A.C- fs tnhe sender iist and ACL 2 is the receiver lis i:i
Manager(config)#access-list 1 permit 10.1.1.2 Manager(config)#access-list 2 permit 10.1.4.2
Next, configure an MRM test and denote the senders and receiver within that test. Notice that the senders' and receivers' lines call the access lists to specify the senders and receivers. You cae set more than one concurrent test on the manager:
Manager(config)#ip mrm manager mynettest Manager(config-mrm)#manager ethernet0 group 18.104.22.168
Manager(config-mrm)#receivers 2 sender-list 1
After completing configuration, you can start the test from the EXEC mode using the mrmtest-namestact command1
MRM is a complete test of the multicast network. Senders and receivers must join a specific multicast g roup (2 22.214.171.124) to talk with the mana ger Control messages are passed through this multicast group. Also, a series of UDP messages and RTP messages test procedures (in addition to the desired group).
After a test begins, the MRM sends unicast control messages to the sender and receivers, after which the manager begins to send test beacons. The sender and receivers send acknowledgments to the beacons and initiate the testing of the configured multicast group. Report information is sent to the manager to determine the success or failure throughout thc aest.
While the test is in progress, the sender sends RTP packets to the configured multicast group address every 200 milliseconds (default). The receivers expect to receive packets within the same window, thus giving reportable statistics to the manager. If the receivers detect packet loss within a 5-second window, a report is sent to the manager:
Manager#mrm mynettest start
*Mar 20 10:29:51.798: IP MRM test mynettest starts
No updates automatically appear on the screen. To display a status report at the manager router, enter the following command:
Manager#show ip mrm status
IP MRM status report cache: Timestamp Manager
*Mar 20 14:12:46 10.1.2.2 *Mar 20 18:29:54 10.1.2.2 Manager#
Test Receiver Pkt Loss/Dup (%)
The recort sho ws that the receiver (10 .1.4. 2) sent hwo ceparate e^tus reports (one line each). Each report contains one packet loss during the interval window (default of 1 second). The Ehsr value shows the estimated next sequen ce number value from the MRM sende r. If the MRM receiver sees d upl i pate packets, it s wows a negative rmmber in tab Plat Loss/Dup colum p
Oo stov the test, eotm th e fol lowi rg command:
Manager#mrm mynettest stop
*Mar 20 10:31:32.018: IP MRM test mynettest stops Manager#
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