No network interfaces found (verifyNetworkConnection)

[Sebastian Roth]

Spooky! Sure your network is fine? Just kidding!

[Wayne Workman]

This just happened to me again on an Optiplex 7010 in BIOS mode. This particular Optiplex has a wireless card in it, and is also hooked up to the wired LAN.

I’m now on r6263 with Fedora 21 server, using undionly.kkpxe and kernel 4.4.1

[Wayne Workman]

I took the wireless card out of the Optiplex 7010 and it still gives the same error. I’ve also tried uploading using different ports on the switch… think I’m going to try a totally different switch next.

[Wayne Workman]

64bit kernel 3.19.3 also failed - but the 7010 did go through the motions of pulling the kernel from the server and loading it - but results in the exact same error…

I’m going to try a different switch now.

[Wayne Workman]

It’s our network. The computer uploads on the first try every time on a different switch.

[MRCUR]

@Wayne-Workman Verify spanning tree portfast mode (Cisco) or admin-edge-port (HP) is enabled on the port(s) you’re connecting the computers to.

[bsmaby]

I’m having the same issue on a Lenovo all in one desktop. I was able to upload from the machine but not able to push an image out to it. I am trying to deploy Windows 10, so not sure if that makes a difference. I have successfully uploaded and deployed windows 7, and was able to upload windows 10, just not deploy as I am getting the error stated above. Any ideas?

I’m on Fog version r6263.
Desktop model: Lenovo C40-05.
FOG Server is running Ubuntu 14.04 LTS
DHCP is a Windows 2003 server.

[Wayne Workman]

@Sebastian-Roth @george1421 @Tom-Elliott

I’ve had more issues with this error, and I’ve done more experimentation.

Turns out, changing switches isn’t the thing that fixes it, changing to any other network port is.

Also - when this problem is experienced (verifyNetworkConnection), that problem lingers on the port itself. It has nothing to do with the connected computer.

Ideas?

[MRCUR]

@Wayne-Workman Have you verified that the problem port on the switch isn’t being put into blocking mode by STP? Running a sh span should give you the port status (at least on an HP switch, Cisco is likely the same). This would “linger” depending on your switch STP config.

[Wayne Workman]

Had a talk with my network people. They said BPDU guard is turned off for the switch I’m using.

Also - just noticed, this particular machine I’m testing with right now (an optiplex 7010) has indicator lights on the NIC port.

When the computer’s firmware is just starting the NIC, the lights come on. There are two lights on the left and right side. one is solid orange, the other blinks yellow.

As soon as bzImage is loaded, the lights turn off and do not come back on and the above OP error is displayed.

Could it be something to do with the kernel turning on the interface? @Sebastian-Roth @Tom-Elliott @george1421 @MRCUR

See the below video, I recorded in a way that you can see the NIC lights:

https://www.youtube.com/embed/Hgn1mozsQsE

[george1421]

Are you booting the 7010 in bios mode or efi. I still have that 7010 on my workbench.

I did note when I was playing with the intel nuc a few weeks ago. It would drop the link light ever stage of the booting process. PXE Rom->iPXE->bzImage This why standard stp is not where we need to be because it takes 20-30 seconds for stp to start forwarding after each transition. Not saying this is your case, but I can understand why.

After watching the video, I see that your system has a longer than normal pause for the pxe roms to init. In my case, I pressed F12 to get the boot menu. When I selected the network boot option, my link light went out for 2 seconds then it started the dhcp process right away. The same for the transition from pxe to iPXE the link light is out for about 2-3 seconds then the process continues.

[Wayne Workman]

@george1421 said:

Are you booting the 7010 in bios mode or efi.

Legacy mode.

[george1421]

Sorry I was editing my previous post, when you posted. I’m only seeing between 2-3 seconds of where the link light is out per transition. And In my office I just have a really old Linksys SLM2008 switch.

[Wayne Workman]

@george1421 I have an old 100 meg unmanaged switch I can put between the computer and the building network… I’ll see if that makes a difference… if it does, the kernel is not at fault.

[george1421]

@Wayne-Workman I think the problem (according to your video) is way before the kernel gets loaded. The unmanaged switch will be a good test. It will stink for download speed, but it will be a good test for link recovery.

[Wayne Workman]

@george1421 The most interesting thing happened. I’m going to explain as best I can the exact sequence of events.

I hooked up this little unmanaged 100 Mbps 5 port switch between the buiding network and this Optiplex 7010. The optiplex was connected to port 1, the building connected to port 5 (not that it matters).

I didn’t get the OP error. Things started working!

I thought, OK, I need to get a video of what it looks like when it’s working properly. So I turn off the computer, and get my phone setup and the switch in just the right spot for filming and then I fire the computer back on.

Neither the NIC on the computer nor port 1 on the switch ever lit up… what?

I traded what building port that port 5 was connected to, and then it worked again. I got a video of that:

https://www.youtube.com/embed/SUJPdjvZEPc

Any ideas? Man this is nuts.

[george1421]

As you were getting setup to video, did you restart the switch or plug the wiring going to the building at all?

In the last video, the booting timing, was similar to what I’m seeing on my bench. Its about 2 seconds between stages. Because you have a dumb switch between the computer and the building wiring, the computer going up and down shouldn’t impact the port forwarding state on the building network. Its not clear why transferring between building side port 5 to another port had any impact other than it would have transitioned the link state on the building switch.

Are you guys using any type of nac or nap?

[Sebastian Roth]

@george1421 said:

Are you guys using any type of nac or nap?

Same question came to my mind! Are you somehow able to get a serial connection on that building switch? Would be most interesting to see what it talks about the link going down/up and possible other messages (NAC related maybe).

@Wayne-Workman said:

Turns out, changing switches isn’t the thing that fixes it, changing to any other network port is.

So this issue only occurs on one switch port (building switch)?? As soon as you plug into a different port on the same switch things are fine? Either your network guys should have a close look at the specific port configuration or they better abandon that port altogether (if it’s just that single one!).

[Wayne Workman]

@Sebastian-Roth said:

So this issue only occurs on one switch port (building switch)?? As soon as you plug into a different port on the same switch things are fine? Either your network guys should have a close look at the specific port configuration or they better abandon that port altogether (if it’s just that single one!).

No, not just one port. Once I get the error message in the OP for any port, that port seems to be permanently voo-doo’d.

I don’t know what nac or nap is. If I ask my network people this, will they know what I’m talking about? We are 100% Cisco end-to-end.

[Sebastian Roth]

Hopefully they have an idea what NAC is: https://en.wikipedia.org/wiki/Network_Admission_Control