multicast - is there a test to check ?

[bread-baker]

Hello
Is there a way to test if multicast is working on a network?

 

[e100]

Hello
Is there a way to test if multicast is working on a network?

On two nodes on the same network:

#apt-get install ssmping

One Node A:

#ssmpingd

One Node B:

#asmping 224.0.2.1 ip_for_other_host_here
asmping joined (S,G) = (*,224.0.2.234)
pinging 192.168.8.6 from 192.168.8.5
  unicast from 192.168.8.6, seq=1 dist=0 time=0.221 ms
  unicast from 192.168.8.6, seq=2 dist=0 time=0.229 ms
multicast from 192.168.8.6, seq=2 dist=0 time=0.261 ms
  unicast from 192.168.8.6, seq=3 dist=0 time=0.198 ms
multicast from 192.168.8.6, seq=3 dist=0 time=0.213 ms
  unicast from 192.168.8.6, seq=4 dist=0 time=0.234 ms
multicast from 192.168.8.6, seq=4 dist=0 time=0.248 ms
  unicast from 192.168.8.6, seq=5 dist=0 time=0.249 ms
multicast from 192.168.8.6, seq=5 dist=0 time=0.263 ms
  unicast from 192.168.8.6, seq=6 dist=0 time=0.250 ms
multicast from 192.168.8.6, seq=6 dist=0 time=0.264 ms
  unicast from 192.168.8.6, seq=7 dist=0 time=0.245 ms
multicast from 192.168.8.6, seq=7 dist=0 time=0.260 ms

If you have multiple interfaces you may also need to pass the -I interfacename option to both asmping and ssmpingd.

 

[bread-baker]

Thank you , that was easy to do.

I think that info should go to wiki, If you want I can put it there, as multicast is needed for clusters.

From my understanding, making sure multicast works before adding a node to a cluster should be done.

 

[e100]

Feel free to add it to the wiki.

There is quite a bit of info about cman and corosync that likely should be compiled on the wiki.
As a community we have a knowledge gap when it comes to clustering.

 

[bread-baker]

see multicast page at http://pve.proxmox.com/wiki/Multicast_notes

Thanks to Stig Venaas , who wrote the programs.