On Sat 11 Dec 2021 at 23:42:38 +0100, Johnny Billquist wrote: > Uh... If broadcast wasn't working, you'd not have working ARP, more or less. > I would expect that people had noticed that a long time ago by now... (There > are other protocols also using broadcasts, but ARP is very fundamental, and > going on all the time, on any machine using ethernet.) I should have added "receiving" since the sending of broadcasts works fine. But ARP replies aren't broadcast, they are unicast to the requestor: 13:49:28.641231 a8:5e:45:yy:yy:yy (oui Unknown) > Broadcast, ethertype ARP (0x0806), length 42: Request who-has fritz.box tell zzz.fritz.box, length 28 13:49:28.642124 08:96:d7:xx:xx:xx (oui Unknown) > a8:5e:45:yy:yy:yy (oui Unknown), ethertype ARP (0x0806), length 60: Reply fritz.box is-at 08:96:d7:xx:xx:xx (oui Unknown), length 46 (output from tcpdump -e -i wm0 arp on another box) So non-working broadcast reception can go unnoticed for a while. Multicast even longer. -Olaf. -- ___ "Buying carbon credits is a bit like a serial killer paying someone else to \X/ have kids to make his activity cost neutral." -The BOFH falu.nl@rhialto
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