Helpful Linux Commands for testing Multicasting
30 May 2019
Finding useful commands for troubleshooting multicasting was difficult because most were not installed on the servers.
Running the following command should display number of incoming and outgoing multicast packets. Running it multiple times should result in the numbers increasing in value.
$ netstat -sgu | grep Mcast
$ netstat -gn
Running ifconfig should display multicast in the resulting output. ifconfig
$ ifconfig eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 ...stuff omitted...
Omping can be used to troubleshoot multicasting. When run on two different servers/VMs it uses multicasting and reports on packet losses when stopped with Ctrl-C.
omping -m <multicast address> -p <multicast port> <This servers IP adddress> <Other servers IP address>
Show IP addresses and Ports that are listening.
netstat -tulpn | grep LISTEN