Because the history is not linear. See https://techcommunity.microsoft.com/t5/networking-blog/aligning-on-mdns-ramping-down-netbios-name-resolution-and-llmnr/ba

Because the history is not linear. See https://techcommunity.microsoft.com/t5/networking-blog/aligning-on-mdns-ramping-down-netbios-name-resolution-and-llmnr/ba-p/3290816 https://techcommunity.microsoft.com/t5/networking-blog/align... it goes like this: 1. MS uses netBios. 2. apple uses bounjour, similar to netbios, but with modern conveniences, like NAT aware. 3. windows add same niceties on top of netbios and call it LLMNR. 4. apple standardize bounjour as mDNS and open it up just because they would have to publish code because of some licenses they offended (but going into this is veering way too much offtopic on your offtopic) 5. everyone standardize on mDNS 6. RedHat (using their fake open source promotion called freedesktop, nee XDG) pushes for LLMNR for god knows why! (well, might be a reason poetering works for MS now) 7. even microsoft abandon LLMNR and netbios in favour of mDNS. everyone is using mDNS. RH/freedesktop/systemd/fwmg (all the same people) chose to base their LAN distribution service logic on LLMNR. 8. RedHat works backward compatibility of LLMNR into mDNS and things get VERY confusing. Or not. Their documentation uses the name interchangeably and honestly, at this point I am not sure of anything and I'm not paid to look at that code for over a year. I wouldn't be surprised if resolved is actually using mDNS but the setting/code is still just "called" LLMNR. /shrug.