I have noticed that my UM 20.04 generates an SNMP broadcast every time I connect my Android phone to USB for file transfer.
tcpdump:
10:32:21.104559 IP myhost.42632 > 255.255.255.255.snmp: GetRequest(58) system.sysDescr.0 system.sysObjectID.0 interfaces.ifTable.ifEntry.ifPhysAddress.1
Thanks to "Ask Ubuntu" forum, solution was easy to find:
[email protected]/etc/sane.d$ grep autodiscovery ./*
grep: ./dll.d: Is a directory
./epson2.conf:net autodiscovery
./epsonds.conf:#net autodiscovery
./kodakaio.conf:### Network: Format is "net IP_ADDRESS [USB_ID]" or "net autodiscovery"
./kodakaio.conf:### Currently autodiscovery seems to not work
./kodakaio.conf:net autodiscovery
./magicolor.conf:### Network: Format is "net IP_ADDRESS [USB_ID]" or "net autodiscovery"
./magicolor.conf:net autodiscovery
It took commenting out net autodiscovery lines to get rid of the SNMP broadcast.
Regards!
Gene