cups-browsed conf attached.
I do not have a /var/log/cups/cups-browsed_log

This bug can be reproduced/observed on a default install by enabling
UFW. The blocked UDP multicast requests start to show up in
/var/log/ufw.log

cups-backend-bjnp is not installed.
There are no special proprietary Canon drivers or software installed. As stated 
above, this occurs in a default install.

If cups-browsed does not trigger these actions and there is no
proprietary Canon software installed, could there be a kernel blob
causing this behaviour ?

** Attachment added: "cups-browsed.conf"
   
https://bugs.launchpad.net/ubuntu/+source/cups-filters/+bug/1671974/+attachment/4928024/+files/cups-browsed.conf

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You received this bug notification because you are a member of Desktop
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https://bugs.launchpad.net/bugs/1671974

Title:
  cups-browsed Generates Excessive Amounts of UDP Multicast Traffic for
  BJNP

Status in cups-filters package in Ubuntu:
  Incomplete

Bug description:
  It appears that the cups-browsed service as of Xenial (version
  1.8.3-2ubuntu3.1) sends an excessive amount of UDP multicast requests
  for ports 8610 (Canon MFNP) and 8612 (Canon BJNP) under unexpected
  conditions and regardless of a presence or lack of Canon printer
  devices on the network.

  This is manifested by enabling UFW, and observing multicast requests being 
blocked that are sent from the host machine's network IPv4 or IPv6 address to 
the multicast address, e.g.
  [UFW BLOCK] IN=wlp3s0 OUT= MAC= SRC=<Machine IPv6> 
DST=ff02:0000:0000:0000:0000:0000:0000:0001 LEN=64 TC=0 HOPLIMIT=1 
FLOWLBL=96642 PROTO=UDP SPT=8612 DPT=8612 LEN=24

  IN= OUT=wlan0 SRC=192.168.90.45 DST=192.168.91.255 LEN=44 TOS=0x00
  PREC=0x00 TTL=64 ID=7742 DF PROTO=UDP SPT=8612 DPT=8610 LEN=24

  Users have observed that the requests can be reproduced when any USB device 
is plugged/unplugged into the computer, regardless of whether the device has 
anything to do with printing:
  https://twitter.com/gertvdijk/status/621790755758178304
  https://bugs.kali.org/view.php?id=3094

  Just Googling "udp 8612", shows are a large number of results on different 
websites of people who have observed this behaviour in firewall and traffic 
logs, and have noticed that it may contribute to network slowdown and latency:
  https://askubuntu.com/questions/867739/what-is-this-traffic/867786
  
https://serverfault.com/questions/667376/watchguard-blocking-internal-udp-packets

  https://jehurst.wordpress.com/2016/01/22/small-victories/ recommends 
disabling the cups-browsed service to stop these requests:
  systemctl stop cups-browsed.service
  systemctl disable cups-browsed.service

  There are probably two things to address here:
  1. Connecting any USB device should not cause these requests unless the 
device is actually a printer or directly related to printing.
  2. Requests independent of connecting USB devices should be rate limited to a 
degree and/or should be dependent on the actual presence of a Canon printer 
configured on the network.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/cups-filters/+bug/1671974/+subscriptions

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