LAN plugin LLMNR (vs mDNS)

Support for Android version of Total Commander

Moderators: white, Hacker, petermad, Stefan2

Post Reply
ramon2000
Junior Member
Junior Member
Posts: 9
Joined: 2021-06-03, 08:44 UTC

LAN plugin LLMNR (vs mDNS)

Post by *ramon2000 »

Hi,

Few days ago I installed the latest version of the LAN plugin (3.30) and the name resolution does not work with my SMB (Raspberry Pi 4) server, but it worked in the previous version.
Anyway, it works with the IP address, so it is not a major issue.

I have tried with different devices (xiaomi phones, teclast tablet and firestick), and checking and unchecking "Using old method for resolving names" (I don't know if this is the right translation into English), but with no success.

I saw that now you use LLMNR, but it seems that by default RPi 4 does not install the server daemon.

I have done some tests (analysing them with wireshark), and it seems that it does support mDNS (multicast DNS), that is used when you append ".local" to the computer name (e.g. my server is "raspberrypi", and if I use "raspberrypi.local", then mDNS is used to look for the IP address instead of DNS, and it does find the address of the "raspberrypi" computer).

I have also seen that my windows 10 uses LLMNR but also mDNS at the same time to resolve names. If I use "raspberrypi" (e.g. "ping raspberrypi"), my windows 10 makes a call to LLMNR with raspberrypi, but also makes mDNS calls (A IPv4 and AAA IPv6) to raspberrypi.local (it adds the .local before making the call).

So the question is if it would also be possible to add mDNS to the name resolution mechanism in the LAN plugin.

Apart from this, thanks in advance, and thanks for Total Commander (and sorry for this long message).
User avatar
ghisler(Author)
Site Admin
Site Admin
Posts: 48005
Joined: 2003-02-04, 09:46 UTC
Location: Switzerland
Contact:

Re: LAN plugin LLMNR (vs mDNS)

Post by *ghisler(Author) »

Few days ago I installed the latest version of the LAN plugin (3.30) and the name resolution does not work with my SMB (Raspberry Pi 4) server, but it worked in the previous version.
That's VERY strange because the new version supports LLMNR in addition to the old methods (DNS, NetBIOS). Maybe LLMNR works but returns an invalid IP address? Do you see anything in the log? You can enable it via Total Commander main menu - Configure near the end of the settings.

I will also check whether I can support mDNS, but you need to find out why the new version fails to find the server, it makes no sense if the older version manages to find it.
Author of Total Commander
https://www.ghisler.com
ramon2000
Junior Member
Junior Member
Posts: 9
Joined: 2021-06-03, 08:44 UTC

Re: LAN plugin LLMNR (vs mDNS)

Post by *ramon2000 »

Christian,

First of all, thank you for your fast answer.

You are right, the plugin does support LLMNR, DNS and NetBIOS (I have checked with wireshark), and it is the same with Windows.

I see that the issue is in my SMB server, openmediavault (OMV), that I changed some days ago from v5 (debian Usul) to v6 (debian Shaitan), and I suppose that since I changed from v5 to v6 I had not used the TC LAN plugin.

I have tested again OMV5 (it's a raspberry pi and it is only changing the sd card) behaves fine, but OMV6 does not, so probably it is an issue with OMV.

I will keep trying to find out where the problem is.

Thanks again, and don't worry by the issue.
User avatar
ghisler(Author)
Site Admin
Site Admin
Posts: 48005
Joined: 2003-02-04, 09:46 UTC
Location: Switzerland
Contact:

Re: LAN plugin LLMNR (vs mDNS)

Post by *ghisler(Author) »

Maybe they disabled LLMNR or NetBIOS because they have some security issues? Anyone can respond to these calls, even a malicious PI or notebook plugged into the internal company LAN.
Author of Total Commander
https://www.ghisler.com
ramon2000
Junior Member
Junior Member
Posts: 9
Joined: 2021-06-03, 08:44 UTC

Re: LAN plugin LLMNR (vs mDNS)

Post by *ramon2000 »

Regarding the LAN, it is my home LAN, and LLMNR or NetBIOS is not disabled in the network.

I have done some research, and it seems that in openmediavault v6 (OMV6) NetBIOS is disabled by default (they disabled it few weeks ago), and I am afraid that LLMNR must also be disabled in OMV6 (or even not installed by default in the raspberry pi) (I have seen that there may be some security issues, so maybe the developer).

Edit: Some clarifications have been done in the previous sentence.
Edit 2: Anyway, from my tests, it seems that my OMV6 does support mDNS.

Anyway, don't worry, and thank you again for your time and your fast answer.
User avatar
ghisler(Author)
Site Admin
Site Admin
Posts: 48005
Joined: 2003-02-04, 09:46 UTC
Location: Switzerland
Contact:

Re: LAN plugin LLMNR (vs mDNS)

Post by *ghisler(Author) »

In beta 2, I have now added mDNS! It seems to work fine with my Raspberry PI.

You can get the beta version via Play Store here:
https://play.google.com/apps/testing/com.ghisler.tcplugins.LAN
Author of Total Commander
https://www.ghisler.com
ramon2000
Junior Member
Junior Member
Posts: 9
Joined: 2021-06-03, 08:44 UTC

Re: LAN plugin LLMNR (vs mDNS)

Post by *ramon2000 »

Christian,
I have just seen the e-mail, and I have already answered it, but I also want to copy the text in the forum:

First of all, thank you very much for your time in improving TC (windows and android versions). Sorry because I didn't see that mDNS was already supported in the beta version.

I have just joined the beta program and downloaded beta 2 to my smartphone.
I will try to test it ASAP and I will tell you something (I have already put it in my task list :) ).
ramon2000
Junior Member
Junior Member
Posts: 9
Joined: 2021-06-03, 08:44 UTC

Re: LAN plugin LLMNR (vs mDNS)

Post by *ramon2000 »

I've just had few time to make some tests and in my case it seems that it is working OK.

With the public plugin, I am not able to connect to my server (raspberry pi 4 with openmediavault 6, OMV6). It "looks up" through different protocols. (I think that OMV6 disables LLMNR and NetBIOS).

With the beta plugin, as soon as it "looks up" mDNS protocol, it connects to the server.
With Wireshark (in a PC, not in the android device) I see that it is sending a right MDNS query to "myservername.local", as expected.

I cannot see the mDNS answer because probably it is not broadcast, so only "myservername" receives it.

Maybe someone else can also test it.

If you need some more test, you can contact me.

Thanks again for your work.
User avatar
ghisler(Author)
Site Admin
Site Admin
Posts: 48005
Joined: 2003-02-04, 09:46 UTC
Location: Switzerland
Contact:

Re: LAN plugin LLMNR (vs mDNS)

Post by *ghisler(Author) »

That's nice to hear! I'm not using any library for mDNS, but implemented it myself, that's why it's important to get feedback whether it works or not. Interestingly, LLMNR and mDNS are actually quite similar.
Author of Total Commander
https://www.ghisler.com
ramon2000
Junior Member
Junior Member
Posts: 9
Joined: 2021-06-03, 08:44 UTC

Re: LAN plugin LLMNR (vs mDNS)

Post by *ramon2000 »

I had never taken a look at mDNS and LLMNR protocols (but I am quite familiar with DNS), and just out of curiosity I have just done a little research and I see that, as you say, all 3 are very similar.

Thanks again,
Post Reply