Arch Linux reporting corrupted names to Router

ThePacman · 2013-09-26 20:39:34

On my Router's settings page, I can view attached devices. It displays their local IP, hostname, MAC addres, and whether they're connected via Ethernet or Wi-Fi.

It seems that Arch linux is not doing a very good job telling its hostname to the router.
We have 8 different devices, running a wide variety of OSes (from Android to embedded to Win 8 to my Linux distros) and Arch is the only one that's ever displayed its hostname incorrectly.

Here's a snapshot of my Router's Attached Devices page:

Wired Devices
# IP Address	Device Name		MAC Address
---------------------------------------------------------
1 192.168.0.8	K?HES-RPI		B8:27:EB:4B:D4:68

Wireless Devices (Wireless intruders also show up here)
# IP Address	Device Name		MAC Address
---------------------------------------------------------
1 192.168.0.10	FAMILYCPU		94:44:52:C1:2F:EA
2 192.168.0.11	FAMILY-LENOVO		20:16:D8:74:EA:8F
3 192.168.0.119	(?ES-INSPIRON-B130	00:14:A5:5B:E7:D3
4 192.168.0.175	JAMES-DROIDX		F8:7B:7A:C9:BA:09
5 192.168.0.192	JAMES-OPTIPLEX-		00:24:01:9B:D3:1A

Wherevere you see a '?', that character is actually corrupted. It looks like a question mark inside a diamond, and if I open it in Nano or Chromium, it appears as 'ï¿½'.

Now, I am 100% sure this is an Arch-specific issue (though not necessarily Arch's fault) because the only two machines to do this are the Raspberry Pi and the Inspiron B130, and the Pi never did it until I switched it over to Arch the other day.

Does anyone know what's causing this or how to fix it? I don't have any special characters in my hostnames, the only non-alphanumeric character is a plain old -, not even the fancy — mark.

Last edited by ThePacman (2013-09-26 20:40:00)

Spider.007 · 2013-09-28 12:43:22

Interesting. What are the actual characters that you expect to be there? Also; what kind of network-manager do you use, is it http://roy.marples.name/projects/dhcpcd ?

ThePacman · 2013-09-28 14:57:06

Spider.007 wrote:

Interesting. What are the actual characters that you expect to be there? Also; what kind of network-manager do you use, is it http://roy.marples.name/projects/dhcpcd ?

I'm using netctl with static IP's for all of my Arch boxes. (There is a DHCP server for the family computers; it's in charge of 192.168.0.{10-99}. I've got free rein over 192.168.0.{2-9,100-254}.) My other computers are running Ubuntu/derivitaves, so they're using whatever network manager Ubuntu uses (but they have been set up with static IP's.)

The hostnames are expected to be 'james-RPi' and 'james-Inspiron-B130'. I don't mind the fact that the router shows them in all caps, just the corrupted characters.

I can use james-RPi.local to connect, so Avahi isn't seeing anything amiss, and nmap reports correct names for all machines as well. The only issues are between the router and the Arch boxes.

Last edited by ThePacman (2013-09-28 15:02:14)

Spider.007 · 2013-09-29 10:39:03

Hmm okay, with static-ip's I'm not sure how your router finds out the hostname (with dhcp it is included in the request from the client) I would suggest nmap -A but I see you already did that. Do you think your router uses avahi to report the hostnames of the machines? Does avahi-browse -alr show the correct hostnames or are they also garbled?

Awebb · 2013-09-29 11:10:37

Caps looks like Avahi or Samba reports a netbios name. How did you set the hostname? What does hostnamectl say? Post your hostname file.

ThePacman · 2013-09-29 20:00:11

Awebb wrote:

Caps looks like Avahi or Samba reports a netbios name. How did you set the hostname? What does hostnamectl say? Post your hostname file.

My hostname, which I set in /etc/hostname (and /etc/hosts) during installation, is james-Inspiron-B130.
The output of hostnamectl is:

   Static hostname: james-Inspiron-B130
         Icon name: computer-laptop
           Chassis: laptop
        Machine ID: 639b92fba1004d01add543fd82ef79c9
           Boot ID: 233aad5935eb4d6f8513fe48fa9af5fb
  Operating System: Arch Linux
            Kernel: Linux 3.10.10-1-ARCH
      Architecture: i686

Last edited by ThePacman (2013-10-01 13:45:42)

ThePacman · 2013-10-07 03:11:36

Spider.007 wrote:

Hmm okay, with static-ip's I'm not sure how your router finds out the hostname (with dhcp it is included in the request from the client) I would suggest nmap -A but I see you already did that. Do you think your router uses avahi to report the hostnames of the machines? Does avahi-browse -alr show the correct hostnames or are they also garbled?

avahi-browse -alr reports the name correctly.

I tried switching the Pi over to DHCP and that didn't fix it.

Something I noticed - today, the laptop's name reported as "unknown". I haven't made any changes, and it seemed to happen and stop happening arbitrarily.

Last edited by ThePacman (2013-10-07 03:13:27)

Jristz · 2013-10-07 05:12:37

systemD spect hostnames to by all in minuscules, and try to change them if not receive it at connect time}
almost this is what I noticed

ThePacman · 2013-10-07 13:06:15

Jristz wrote:

systemD spect hostnames to by all in minuscules, and try to change them if not receive it at connect time}
almost this is what I noticed

I'm sorry, could you clarify?

It seems you're saying that systemd expects all the hostnames to be in.. little endian? And it tries to fix them, resulting in corrupted hostnames?

Is there anything I can do to fix this?

Awebb · 2013-10-07 13:17:22

ThePacman wrote:

It seems you're saying that systemd expects all the hostnames to be in.. little endian? And it tries to fix them, resulting in corrupted hostnames?

Well...

Awebb wrote:

Caps looks like Avahi or Samba reports a netbios name.

Does either, Avahi or Samba run in the background?

falconindy · 2013-10-07 13:18:29

ThePacman wrote:

Jristz wrote:
systemD spect hostnames to by all in minuscules, and try to change them if not receive it at connect time}
almost this is what I noticed
I'm sorry, could you clarify?
It seems you're saying that systemd expects all the hostnames to be in.. little endian? And it tries to fix them, resulting in corrupted hostnames?
Is there anything I can do to fix this?

I think "miniscules" means lowercase, but this isn't true -- systemd will not touch capital letters. Regardless, "FOOBAR" and "foobar" are exactly the same as far as DNS is concerned.

mrunion · 2013-10-07 13:42:14

My router (a Netgear) acts like that too, ThePacman. My computer names are simple -- things like "bonehammer" and "deputycoder" -- show up on the router control interface with the "question mark in a diamond" in place of some of the letters. I will take a screenshot from home when I get there.

I just brushed it off as "weirdness" and left it at that. FWIW, it hasn't ALWAYS done this. I don't log into my router all the time but it seems it was fine in July but not in September. I know -- that's not too much help, huh?!?

ThePacman · 2013-10-07 16:18:54

Awebb wrote:

Does either, Avahi or Samba run in the background?

Yes, Avahi runs in the background. Samba is not installed.
Avahi gathers the hostnames properly - caps and all, non-truncated, uncorrupted.

For non-Arch machines, the router reports the hostnames correctly, with the only issue being that they're in all caps and truncated to 15 chars (which is probably just a design issue on the router's part.)

falconindy · 2013-10-07 16:55:04

I'd be suspicious of your DHCP client since that's what's responsible for reporting the hostname back to the router....

Awebb · 2013-10-07 17:30:16

falconindy wrote:

I'd be suspicious of your DHCP client since that's what's responsible for reporting the hostname back to the router....

Some routers, including mine, use netbios names published by "zeroconf stuff" like avahi and samba, ignoring the proper DHCP hostname. This is why I mentioned it. Upper case hostnames look like ancient netbios to me, this is why I'd try to disable all the "zeroconf-y" stuff first.

mrunion · 2013-10-07 17:35:11

I'm not home yet, so I haven't tried any suggestions. But sould you give me any guidance to what I should look for in the Avahi or Zeroconf stuff? FWIW, I run Cinnamon/Gnome (but KDE is installed, if that matters).

Or should I just get into the Wiki and look at Zeroconf or Avahi?

Awebb · 2013-10-07 20:14:04

I'd stop the service, delete the lease in the router and reconnect the Arch box, so it will grab a new release.

But now I think about it, I recently had the problem, that my netbook did not report a hostname at all, although the hostname was set and was even configured seperately in the dhcpcd config file. I did not really solve it, I can edit the host list on the router.

mrunion · 2013-10-08 03:02:41

I check and SAMBA was not running.

avahi-browse -alr reported my machine name correctly as "bonehammer".

FWIW, two devices in my home have the issue. Those two devices are running Arch and ar updated at least weekly. All other devices are fine -- and two of those are running Arch. But since those two are the kids' machines, I don't update them often.

Arch Linux

#1 2013-09-26 20:39:34

Arch Linux reporting corrupted names to Router

#2 2013-09-28 12:43:22

Re: Arch Linux reporting corrupted names to Router

#3 2013-09-28 14:57:06

Re: Arch Linux reporting corrupted names to Router

#4 2013-09-29 10:39:03

Re: Arch Linux reporting corrupted names to Router

#5 2013-09-29 11:10:37

Re: Arch Linux reporting corrupted names to Router

#6 2013-09-29 20:00:11

Re: Arch Linux reporting corrupted names to Router

#7 2013-10-07 03:11:36

Re: Arch Linux reporting corrupted names to Router

#8 2013-10-07 05:12:37

Re: Arch Linux reporting corrupted names to Router

#9 2013-10-07 13:06:15

Re: Arch Linux reporting corrupted names to Router

#10 2013-10-07 13:17:22

Re: Arch Linux reporting corrupted names to Router

#11 2013-10-07 13:18:29

Re: Arch Linux reporting corrupted names to Router

#12 2013-10-07 13:42:14

Re: Arch Linux reporting corrupted names to Router

#13 2013-10-07 16:18:54

Re: Arch Linux reporting corrupted names to Router

#14 2013-10-07 16:55:04

Re: Arch Linux reporting corrupted names to Router

#15 2013-10-07 17:30:16

Re: Arch Linux reporting corrupted names to Router

#16 2013-10-07 17:35:11

Re: Arch Linux reporting corrupted names to Router

#17 2013-10-07 20:14:04

Re: Arch Linux reporting corrupted names to Router

#18 2013-10-08 03:02:41

Re: Arch Linux reporting corrupted names to Router

Board footer