You have been subscribed to a public bug: 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. ** Affects: cups (Ubuntu) Importance: Undecided Status: Confirmed ** Tags: xenial -- CUPS - Excessive Amounts of UDP Multicast Traffic for BJNP https://bugs.launchpad.net/bugs/1671974 You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to cups in Ubuntu. -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
