Pings to Multicast Address
Maybe I am using the wrong verification process but I typically like to use extended pings to a given multicast address to verify my multicast tasks. It will depend on the task but usually throwing an igmp join command on one end and sending pings from another is usually the easiest way to verify.
The part I'm having a difficulty time with is that I never seem to get 100% consistent results with this approach and other times it doesn't seem to work at all, and I don't understand why.
I've read through this blog entry which is very informative and he even provides specifics on sending pings to a multicast address, however I'm still not seeing consistent results. I've not been able to find any other resource out there that discusses this in detail.
I've learned that you must do an extended ping or else your multicast ping traffic goes out every interface. And also I seem to get better results if I do the extended ping from the DR on the given interface I'm sending the pings from. Since the DR is responsible for the registration process to the RP, if you source pings from a different router on that subnet, the DR ends up sending them to the RP encapsulated as unicast anyway. And the unicast responses come back to the DR and then DR sends them onto the local subnet so the originating router should be able to respond to that. So sourcing them from the DR takes that step out of the picture.
IDK, maybe I should not worry about this as much as I am but usually if I dig hard enough there is a reason why something is doing what it does, but for sending pings to a multicast address it is not adding up for me. Any feedback is approciated, thanks.