Confirming source-routed multicast is dead on the public Internet

Sean Donelan sean at
Thu Aug 2 15:27:49 UTC 2018

Thanks to everyone that helped.  Off-list I heard from network engineers 
at several global Internet providers. They all confirmed that multicast 
is no longer supported on their public Internet backbones, no matter what 
their sales people might say. If someone opened a multicast trouble 
ticket, likely no one in their NOC would know what to do with it. They 
acknowledged there might be some old multicast configs on Internet facing 
routers, and eventually they'll clean those out.

Backbone network engineers are fairly blunt.

Multicast is being used in various private IP networks. It seems to work 
very well for satellite content distribution because multicast doesn't 
require ack's. Enterprise networks also use multicast.

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