It is hard to prove a negative. So let’s prove a positive. One of the largest (2nd largest?) transit networks on the planet just affirmatively stated they filter at their border. It is now possible to state that multicast is not ubiquitous on the Internet.
If any other large transit network (L3, GTT, HE, Cogent, etc.) would like to confirm they filter at their borders as well, that would put the final nail in the coffin. -- TTFN, patrick > On Jul 31, 2018, at 15:15, Job Snijders <j...@ntt.net> wrote: > > On Tue, 31 Jul 2018 at 23:29, Sean Donelan <s...@donelan.com> wrote: > >> Its tought to prove a negative. I'm extremely confident the answer is yes, >> public internet multicast is not viable. I did all the google searches, >> check all the usual CAIDA and ISP sites. IP Multicast is used on private >> enterprise networks, and some ISPs use it for some closed services. >> >> I got sent back with a random comment from a senior official saying "but >> I heard different." I bit my tongue, and said I would double (now >> quadruple) check. >> >> If any ISPs have working IP source-routed multicast on the public >> Internet that I missed, or what I got wrong. That's what content >> distribution networks (cdn's) are for instead. > > > > AS 2914 is working to fully dismantle all its Internet multicast related > infrastructure and configs. All MSDP sessions have been turned off, we have > deny-all filters for the multicast AFI, and the RPs have been shut down. > > For years we haven’t seen actual legit multicast traffic. Also the > multicast “Default-Free Zone” has always been severely partitioned. Not all > the players were peering with each other, which led to significant > complexity for any potential multicast source. > > Reasoning behind turning it off is that it limits the attack surface > (multicast can bring quite some state to the core), reduces the things we > need to test and qualify, and by taking this off the RFPs we can perhaps > consider more vendors. > > However, as you noted; multicast within a single administrative domain > (such as an access network distributing linear TV), or confined to > purpose-built L3VPNs very much is a thing. On the public Internet multicast > seems dead. > > Kind regards, > > Job
