Attaching strace to the running avahi-daemon (<PID> is process ID of avahi-daemon)
sudo strace -s 65535 -p <PID> 2>&1 | tee log and stopping CUPS with sudo stop cups shows that avahi-daemon still sends out (or at least tries) broadcast packets with the print queues: sendmsg(13, {msg_name(16)={sa_family=AF_INET, sin_port=htons(5353), sin_addr=ine t_addr("224.0.0.251")}, msg_iov(1)=[{"\0\0\0\0\0\31\0\0\0\0\0\0\31Generic PostSc ript @ till\4_ipp\4_tcp\5local\0\0\377\0\1%HP Photosmart Pro B8800 series @ till \300&\0\377\0\1!HP Photosmart C8100 series @ till\10_printer\300+\0\377\0\1!HP P hotosmart C8100 series @ till\5_ipps\300+\0\377\0\1!HP Photosmart C8100 series @ till\300&\0\377\0\1!HP Photosmart C5200 series @ till\300\211\0\377\0\1!HP Phot osmart C5200 series @ till\300\272\0\377\0\1!HP Photosmart C5200 series @ till\3 00&\0\377\0\1\35EPSON Stylus COLOR 880 @ till\300\211\0\377\0\1\35EPSON Stylus C OLOR 880 @ till\300\272\0\377\0\1\35EPSON Stylus COLOR 880 @ till\300&\0\377\0\1 \36HP_Color_LaserJet_2600n @ till\300\211\0\377\0\1\36HP_Color_LaserJet_2600n @ till\300\272\0\377\0\1\36HP_Color_LaserJet_2600n @ till\300&\0\377\0\1\rHP Fax @ till\300\211\0\377\0\1\rHP Fax @ till\300\272\0\377\0\1\rHP Fax @ till\300&\0\3 77\0\1'Hewlett-Packard HP LaserJet 3390 @ till\300\211\0\377\0\1'Hewlett-Packard HP LaserJet 3390 @ till\300\272\0\377\0\1'Hewlett-Packard HP LaserJet 3390 @ ti ll\300&\0\377\0\1'Hewlett-Packard HP LaserJet 1020 @ till\300\211\0\377\0\1'Hewl ett-Packard HP LaserJet 1020 @ till\300\272\0\377\0\1'Hewlett-Packard HP LaserJe t 1020 @ till\300&\0\377\0\0013Hewlett-Packard HP Color LaserJet CM3530 MFP @ ti ll\300\211\0\377\0\0013Hewlett-Packard HP Color LaserJet CM3530 MFP @ till\300\2 72\0\377\0\1", 1029}], msg_controllen=28, {cmsg_len=28, cmsg_level=SOL_IP, cmsg_ type=, ...}, msg_flags=0}, 0) = 1029 Remote machines do not see any Avahi broadcast from the machine where avahi-daemon is spinning on 100% CPU. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1059286 Title: avahi-daemon takes 100% CPU right after boot To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1059286/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs