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That’s the nice thing about mDNS. No flooding of anything since it’s multicast and not broadcast.
by ulope 3y ago
That’s the nice thing about mDNS. No flooding of anything since it’s multicast and not broadcast.
- deleted 3y ago[deleted]
- zamadatix 3y agoIt would be nice... if it were actually "real" multicast :). It's instead link-local multicast, which has none of the filtering advantages of traditional IP multicast (i.e. no group joining via IGMP is performed for the switches/routers to be able learn who actually needs to listen) https://community.cisco.com/t5/switching/route-igmp-link-local-groups/td-p/2529166 https://community.cisco.com/t5/switching/route-igmp-link-loc... https://community.cisco.com/t5/switching/multicast-on-the-lan/td-p/3859331#:~:text=To%20be%20noted%20IGMP%20snooping%20does%20not%20process%20link%20local%20multicast%20addresses%20224.0.0.X%20that%20are%20still%20fllooded https://community.cisco.com/t5/switching/multicast-on-the-la.... The advantage of link-local multicast over a plain broadcast is it gives a unique address (IP and multicast) so the clients themselves can more easily filter them. That's about it. An mdns aware router just enables MORE flooding to happen (across subnet boundaries, where link-local is not supposed to go).