“No Route” to the network or to the host

[toddkrein]

I’m running stock Ubuntu 22.04LTS on two machines, and Windows 11 on my laptop. Everyone is on the same subnet, and plugged into the same switch. The firewalls are turned off on the Linux boxes, and NoMachine has been added to the Windows Defender access list. Everyone can ping and SSH everyone else.

The Windows box can connect to itself, but times out trying to connect to either of the Linux boxes.

Both Linux boxes can connect to the Windows box.

The Linux boxes cannot connect to each other, they get the message “No Route to the network or to the host.”

Anyone have any ideas?

What I need is to get the Linux desktops accessible from the laptop.

Thanks!

[Britgirl]

So,

Windows local host OK
Windows to Linux (both) Not OK
Linux (both) to Windows OK

This is probably something to do with the package you have installed. Did you install the free edition everywhere? Make sure you didn’t install an Enterprise Client package which does not include the server component. Also, check that you downloaded and installed the correct software package for your system’s architecture. So if you have a 64-bit system, and installed a 32-bit package, remove it and download and install the 64-bit package.

If everything is correct, send us the server side logs (one of the Linux systems) after you have reproduced the problem. So enable debug according to the instructions here, https://kb.nomachine.com/DT07S00243, connect from Windows or the other Linux host, reproduce the error and then gather logs. You can send them to us via email (forum[at]nomachine[dot]com) or attach here.

[toddkrein]

Thanks for the response. I’m not sure it’s the package. The logs don’t show any sort of attempted connection at all.

I looked using wireshark, and I see lots of ICMP errors when the Windows host tries to access the Linux machine.

Another data point, I can’t get the linux boxes to connect to each other either. That’s when I get the “No Route” error. From Win to Ubuntu I get a time out.

Is NoMachine using some sort of discovery protocol to find the other host, or is it going direct to TCP:4000?

Attachments:

1. NoMachine-log-2024.10.31-15.09.53.zip

[toddkrein]

A little more sleuthing… the Linux host is rejecting the packets to port 4000. Enclosed is the pcap trace from wireshark. The ‘ufw’ firewall was off. I turned it on and allowed port 4000, no difference.

Attachments:

1. fail-208.zip

[toddkrein]

The install file on the Linux machines is nomachine_8.14.2_1_amd64.deb

[toddkrein]

Oh. OK, I found it.

Ubuntu has at least three firewall options, and I just found the third. The ports need to be opened in order for NoMachine to work.

sudo firewall-cmd –permanent –add-port=4000/tcp

sudo firewall-cmd –permanent –add-port=4000/udp

sudo firewall-cmd –reload

 

Since I’m just running Ubuntu out of the box (just used the defaults), I’m surprised no one else has run into this.

Might the updates to the firewall be added to the install scripts, or the install instructions?

thanks!

[toddkrein]

Last comment:

sudo firewall-cli –state

 

will tell you if it’s running.

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