Pi-top can''t find local network devices by name

pi-top [4]
#1

Here is my story: I just got my robot-kit this morning, and as I was preparing to explore it, I proceeded to update my OS, (as well as the firmware). All seemed to go well, but after the reboot, I found that none of the other devices were contactable by name (i.e., “ssh other-pi”). I can contact it by using it’s ip address, but of course, that is less convenient, and it used to work, before I updated the system software.

Other that manually entering the names and addresses in ‘/etc/hosts’ (which, as I noted above, was not required prior to this morning…), does anyone have suggestions as to how to correct this?

Edit: as an aside, though possibly related, is the fact that the Wi-Fi icon no longer shows the expected number of bars.

JimT

Keep settings between boots
#2

@JDTucker can you try running sudo raspi-config again and changing the hostname in there to see if that resolves it? I’m not entirely sure if this is related to the update or not so I’ll have to do some investigation.

Also, the WiFi icon doesn’t have bars anymore, it’s solid white on a grey background - if your WiFi signal gets weaker you should see the solid white part getting smaller

#3

@duwudi Gave that a try, both with the gui configuration, and with raspi-config. No joy. Some strange things, however.

  1. When I tried to VLC into the box, I was refused entry for a bad user/password, a fact I know not to be true. Setting the name back resulted in normal operation.
  2. sudo hostname new-name seemed to result in a name change, but that did NOT survive a reboot. I have not tested this extensively, however.
  3. The name of my router DOES resolve properly, but none of my other existing devices.
  4. Saved SMB locations in the File Manager resolve properly, at least when the original hostname is in use. I need to test this more.
  5. Various executable files fail (ping, mount, ssh) with unable to resolve name or service.
  6. Only vaguely related: I get a static-y crackle-y sound from the pi-top speaker every time I connect with VLC. There have been one or two other times, but I haven’t quite isolated them.

Notes about pi-top and my network: The pi-top has been integrated into my network for more than a year, with no problems. It is not one of my ‘always-on’ devices, being powered up only when I’m working with it. As such, there are usually updates to perform when I turn it on. This last two months, I’ve been working on other things, so there were at least two kernel updates in the meantime. The problem I have described here started with the latest set of updates (about 130 of them), including both the Sirius, and the December kernel, as well as the foundation code update.

My next step will be to try a new sdcard with fresh flash to see what happens, though I expect to work perfectly well.---- EDIT: Just finished this process, and, guess what? No JOY! I am still not resolving names on my local net, unless the name is appended with .local!

THIS JUST IN: Appending .local to the network device name seems to work, which explains why File Manager saved locations work.

JimT

#4

@JDTucker ok, glad you managed to fix the problem!

With regards to point 6, we are seeing (hearing!) that too - it seems to be correlated with RPi changing to use PulseAudio. We are currently trying to figure out how to fix it and will roll out an update when we do.

#5

@duwudi I really don’t see it as a “fixed problem”, but rather a very inconvenient work-around. Since none of the other PIs on my network (all running the same raspberry pi os revision) exhibit any such issue (nor did my pi-top, before the latest update), and a brand new installation of Sirius does the same thing, there seems to be but one conclusion. Is there somewhere I should be filing a bug report?

JimT

#6

The problem is that the OS is putting the DNS servers in the wrong order. Take a look at /etc/resolv.conf

It’s putting 1.1.1.1 etc at the top, with your own network settings under that.

I have edited /etc/resolv.conf.head and commented out the defaults there. I’ll see in the morning if that has fixed the issue.

2 Likes
#7

@JDTucker apologies, I misunderstood your message - I didn’t realise your other devices didn’t exhibit this behaviour on your network.

I also tested my own pi-top with a custom hostname and I don’t get any issues using just hostname with either VNC, SSH or ping - maybe our local networks are configured differently, I need to check that.

Can you try @GeekyTim’s suggestion and see if that helps? If that resolves it then I can get a ticket created in our internal system.

(FYI I’ve also just asked the team where these types of bug reports should go, will let you know when I find out)

#8

@duwudi Two things:

  1. I did try @GeekyTim‘s fix, but it didn’t seem to help.
  2. If you want, I could ‘dd’ the sdcard on which I put a fresh distro of Buster/Sirius (the one which also exhibits the issue), and send it to you, but I’d need some command-line help to get it right.

JimT

#9

JD - you need to edit the /etc/resolv.conf.head file.

I did that and it worked for me between boots!

Just the screen resolution to go.

#10

Ah! I edited the wrong file! TNKS!

JimT

#11

@duwudi: HeyHey! Thanks to @GeekyTim’s /etc/resolv.conf.head edit fix seems to fix the issue! Ping, ssh, and scp all work the way they should, and do, on my other PIs.

JimT

#12

@JDTucker excellent! Nice work @GeekyTim, this is awesome.

@pi-topJorge, let’s look into if this fix is something we can do automatically for the OS in future :+1: