IMHO currently the worst bugs are in discoveryd, which replaces mDNSResponder for Bonjour.
If you remove a service on OSX 10.10 it's removal will be broadcast. But it doesn't stop there. No... Most of the time the service will be published again after that and after a second or so it will be finally removed. How the hell did this pass even the most basic QA checks?!
discoveryd is shit. The unofficial no broadcast argument breaks WiFi. You can't disable discoveryd, or it breaks DNS and DHCP.
If there's somwthing you want to block (multicast DNS), get icefloor and/or (Hand Off OR Little Snitch). I use the former and latter.former. OSX Yosemite contains the awesome pf firewall forked from FreeBSD which was forked from OpenBSD. (Apple send some cash to FreeBSD and OpenBSD plz.)
If you remove a service on OSX 10.10 it's removal will be broadcast. But it doesn't stop there. No... Most of the time the service will be published again after that and after a second or so it will be finally removed. How the hell did this pass even the most basic QA checks?!