Arch Linux

lenhuppe

Member

From: New Hampshire USA

Registered: 2018-12-10

Posts: 282

Website

SOLVED LLMNR intermittent after switching to NetworkManager

I recently switched from systemd-networkd to NetworkManager on my two home systems. The wired connections are working great but the LLMNR is not. I am aware of possible link local and TLD conflicts so I tried changing my hostname-mode settings using the information found here: https://man.archlinux.org/man/NetworkManager.conf.5

/etc/NetworkManager/NetworkManager.conf

[connection]
connection.llmnr=2
hostname-mode=dhcp

When I check my connection I get the following:

enp6s0: connected to Wired connection 1
	"Intel I225-V"
	ethernet (igc), 50:EB:F6:7F:F9:AF, hw, mtu 1500
	ip4 default
	inet4 192.168.1.189/24
	route4 default via 192.168.1.1 metric 100
	route4 192.168.1.0/24 metric 100
	inet6 fe80::2933:f8a7:4f5e:9939/64
	route6 fe80::/64 metric 1024

lo: unmanaged
	"lo"
	loopback (unknown), 00:00:00:00:00:00, sw, mtu 65536

DNS configuration:
	servers: 192.168.1.1
	domains: home.net
	interface: enp6s0

Use "nmcli device show" to get complete information about known devices and
"nmcli connection show" to get an overview on active connection profiles.

Consult nmcli(1) and nmcli-examples(7) manual pages for complete usage details.

If I reboot both systems I can connect via SSH and SMB. However if I disconnect I cannot reconnect.

So far I have tried setting hostname-mode to 'dhcp' and 'none' but neither setting solves the problem.

Am I looking in the wrong place?

Last edited by lenhuppe (2022-10-30 18:08:49)

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"I'm suspicious of people who don't like dogs, but I trust a dog when it doesn't like a person."  -- Bill Murray

-thc

Member

Registered: 2017-03-15

Posts: 775

Re: SOLVED LLMNR intermittent after switching to NetworkManager

Are you aware that you also need a working LLMNR responder in your subnet?

lenhuppe

Member

From: New Hampshire USA

Registered: 2018-12-10

Posts: 282

Website

Re: SOLVED LLMNR intermittent after switching to NetworkManager

Are you aware that you also need a working LLMNR responder in your subnet?

I had forgotten about that since resolved has a responder built in. NetworkManager can use resolved but there is a plugin which I needed to enabled for that.

I ended up creating two configuration files:

/etc/NetworkManager/conf.d/dns.conf
-->
# use resolved
[main]
plugins=dns-systemd-resolved

/etc/NetworkManager/conf.d/llmnr.conf
-->
# enable LLMNR
[connection]
connection.llmnr=2

In testing.

UPDATE:

It worked for a while and then stopped.

Last edited by lenhuppe (2022-10-30 18:09:38)

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"I'm suspicious of people who don't like dogs, but I trust a dog when it doesn't like a person."  -- Bill Murray

lenhuppe

Member

From: New Hampshire USA

Registered: 2018-12-10

Posts: 282

Website

Re: SOLVED LLMNR intermittent after switching to NetworkManager

Updated on 11-11-22

From the information I found It appears that NetworkManager has LLMNR disabled.

I am using systemd-resolved and by default it has LLMNR enabled with a responder.

Unlike systemd-networkd I did not need to configure LLMNR when setting up NetworkManager.

Last edited by lenhuppe (2022-11-11 18:38:10)

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"I'm suspicious of people who don't like dogs, but I trust a dog when it doesn't like a person."  -- Bill Murray