Disable builtin mDNS server

[becm]

The Multicast DNS component of Chromium(listening on port 5353) has been resistant to getting disabled.

It seems adding the command line option --disable-features=MediaRouter seems (for now?) the best/only way to turn it off.

Creating new topic for documentation purposes, all existing mentions I found here are in archived topics.
And maybe people like @pathduck are still looking for a way to get rid of it.

[Pathduck]

@becm Yes, looks like you're right - good find!

Not sure I'm that concerned about disabling it - but nice that it can be done.

Guess I never got anyone with Linux to do the same and run a netstat on their system

[becm]

@Pathduck too lazy to install netstat but ss -lwut (all listening TCP, UDP and RAW sockets):

icmp6 UNCONN 0    0          *%enp3s0:ipv6-icmp           *:*
udp   UNCONN 0    0     127.0.0.53%lo:domain        0.0.0.0:*
udp   UNCONN 0    0 192.168.<>%enp3s0:bootpc        0.0.0.0:*
udp   UNCONN 0    0 [fe80::<>]%enp3s0:dhcpv6-client    [::]:*
tcp   LISTEN 0 4096     127.0.0.53%lo:domain        0.0.0.0:*

Vivaldis mDNS was the last remaining user process.

Of course there is a load of local UNIX and NETLINK sockets, but nothing for potential remote access.