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Comment by skykooler | Hacker News Reader

Of course, not all routers (particularly combo router/modems provided by your ISP) support multicast DNS, so often this isn't an option.

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I haven't seen a home router that doesn't support Bonjour in the past decade. It's a fundamental component in the Apple ecosystem and any home router that didn't allow one to wireless print from their iPhone would be considered broken.

Do people really wireless print from their iPhone? Not once can I say I've wanted to print from my phone.

Yes iphone wireless printing works great esp PDF attachments in emails. I use it quite a bit.

The router doesn't really need to support anything, the mDNS packets just flood the bridge domain directly between clients like any other flooded packet.

That’s the nice thing about mDNS. No flooding of anything since it’s multicast and not broadcast.

It 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-loc... 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).

Starlink routers don't forward mDNS packets between clients, and neither did our Fios router before that.

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