Using omping to test multicast connectivity in clusters

Use the omping tool to test basic multicast connectivity between Eclipse Amlen servers in a cluster.

Install the omping tool on all the servers in the cluster. On each server, enter the following command:
yum install omping

The omping tool is available in the omping package that is provided with the base operating system. You can use it to test basic multicast connectivity between the Eclipse Amlen servers in a cluster. For more information about the omping tool, read the man page.

Run the omping tool on the servers between which you are testing multicast connectivity.
The following example demonstrates the use of the omping tool to test multicast connectivity between two servers, Server A and Server B, that are in a cluster and shows example output from the tool.
Run the omping tool on both servers:
  • For example, on Server A:
    omping -m <multicast or broadcast address> -p <cluster multicast discovery port> <IP of local cluster control interface> <cluster control IP address of Server B>
  • For example, on Server B:
    omping -m <multicast or broadcast address> -p <cluster multicast discovery port> <IP of local cluster control interface> <cluster control IP address of Server A>
The following example output from the tool shows that multicast connectivity exists between Server A and Server B. You can see that multicast packet loss is 0 per cent:
  • Output on Server A:
    [root@servera ˜]$ omping -m 239.192.97.105 -p 9106 10.120.16.122 10.120.16.113
    10.120.16.113 : waiting for response msg
    10.120.16.113 : joined (S,G) = (*, 239.192.97.105), pinging
    10.120.16.113 :   unicast, seq=1, size=69 bytes, dist=0, time=0.075ms
    10.120.16.113 : multicast, seq=1, size=69 bytes, dist=0, time=0.087ms
    10.120.16.113 :   unicast, seq=2, size=69 bytes, dist=0, time=0.127ms
    10.120.16.113 : multicast, seq=2, size=69 bytes, dist=0, time=0.138ms
    10.120.16.113 :   unicast, seq=3, size=69 bytes, dist=0, time=0.117ms
    10.120.16.113 : multicast, seq=3, size=69 bytes, dist=0, time=0.123ms
    10.120.16.113 :   unicast, seq=4, size=69 bytes, dist=0, time=0.136ms
    10.120.16.113 : multicast, seq=4, size=69 bytes, dist=0, time=0.189ms
    ˆC
    10.120.16.113 :   unicast, xmt/rcv/%loss = 4/4/0%, min/avg/max/std-dev = 0.075/0.114/0.136/0.027
    10.120.16.113 : multicast, xmt/rcv/%loss = 4/4/0%, min/avg/max/std-dev = 0.087/0.134/0.189/0.042
    [root@servera˜]$
  • Output on Server B:
    Server B[root@serverb ˜]$ omping -m 239.192.97.105 -p 9106 10.120.16.122 10.120.16.113
    10.120.16.122 : waiting for response msg
    10.120.16.122 : waiting for response msg
    10.120.16.122 : waiting for response msg
    10.120.16.122 : joined (S,G) = (*, 239.192.97.105), pinging
    10.120.16.122 :   unicast, seq=1, size=69 bytes, dist=0, time=0.082ms
    10.120.16.122 : multicast, seq=1, size=69 bytes, dist=0, time=0.092ms
    10.120.16.122 :   unicast, seq=2, size=69 bytes, dist=0, time=0.064ms
    10.120.16.122 : multicast, seq=2, size=69 bytes, dist=0, time=0.092ms
    10.120.16.122 :   unicast, seq=3, size=69 bytes, dist=0, time=0.112ms
    10.120.16.122 : multicast, seq=3, size=69 bytes, dist=0, time=0.143ms
    ˆC
    10.120.16.122 :   unicast, xmt/rcv/%loss = 3/3/0%, min/avg/max/std-dev = 0.064/0.086/0.112/0.024
    10.120.16.122 : multicast, xmt/rcv/%loss = 3/3/0%, min/avg/max/std-dev = 0.092/0.109/0.143/0.029
    [root@serverb˜]$
The following example output from the tool shows no multicast connectivity between Server A and Server B. You can see that multicast packet loss is 100 per cent:
  • Output on Server A:
    [root@servera ˜]$ omping -m 239.192.97.105 -p 9106 10.120.16.122 10.142.70.133
    10.142.70.133 : waiting for response msg
    10.142.70.133 : joined (S,G) = (*, 239.192.97.105), pinging
    10.142.70.133 :   unicast, seq=1, size=69 bytes, dist=3, time=0.120ms
    10.142.70.133 :   unicast, seq=2, size=69 bytes, dist=3, time=0.189ms
    10.142.70.133 :   unicast, seq=3, size=69 bytes, dist=3, time=0.187ms
    10.142.70.133 :   unicast, seq=4, size=69 bytes, dist=3, time=0.170ms
    10.142.70.133 :   unicast, seq=5, size=69 bytes, dist=3, time=0.199ms
    10.142.70.133 :   unicast, seq=6, size=69 bytes, dist=3, time=0.183ms
    10.142.70.133 :   unicast, seq=7, size=69 bytes, dist=3, time=0.184ms
    10.142.70.133 :   unicast, seq=8, size=69 bytes, dist=3, time=0.158ms
    10.142.70.133 :   unicast, seq=9, size=69 bytes, dist=3, time=0.184ms
    ˆC
    10.142.70.133 :   unicast, xmt/rcv/%loss = 9/9/0%, min/avg/max/std-dev = 0.120/0.175/0.199/0.024
    10.142.70.133 : multicast, xmt/rcv/%loss = 9/0/100%, min/avg/max/std-dev = 0.000/0.000/0.000/0.000
    [root@servera˜]$
  • Output on Server B:
    [root@serverb ˜]$ omping -m 239.192.97.105 -p 9106 10.142.70.133 10.120.16.122
    10.120.16.122 : waiting for response msg
    10.120.16.122 : waiting for response msg
    10.120.16.122 : waiting for response msg
    10.120.16.122 : joined (S,G) = (*, 239.192.97.105), pinging
    10.120.16.122 :   unicast, seq=1, size=69 bytes, dist=3, time=0.116ms
    10.120.16.122 :   unicast, seq=2, size=69 bytes, dist=3, time=0.132ms
    10.120.16.122 :   unicast, seq=3, size=69 bytes, dist=3, time=0.162ms
    10.120.16.122 :   unicast, seq=4, size=69 bytes, dist=3, time=0.133ms
    10.120.16.122 :   unicast, seq=5, size=69 bytes, dist=3, time=0.128ms
    10.120.16.122 :   unicast, seq=6, size=69 bytes, dist=3, time=0.133ms
    10.120.16.122 :   unicast, seq=7, size=69 bytes, dist=3, time=0.132ms
    10.120.16.122 :   unicast, seq=8, size=69 bytes, dist=3, time=0.134ms
    ˆC
    10.120.16.122 :   unicast, xmt/rcv/%loss = 8/8/0%, min/avg/max/std-dev = 0.116/0.134/0.162/0.013
    10.120.16.122 : multicast, xmt/rcv/%loss = 8/0/100%, min/avg/max/std-dev = 0.000/0.000/0.000/0.000
    [root@serverb˜]$