Using omping to test multicast connectivity in clusters

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Use the omping tool to test basic multicast connectivity between IBM® IoT MessageSight servers in a cluster.

Before you begin

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

About this task

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 IBM IoT MessageSight servers in a cluster. For more information about the omping tool, read the man page.

Procedure

Run the omping tool on the servers between which you are testing multicast connectivity.

Example

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˜]$