Display Ethernet card connection speed

  • Our university networks are poorly maintained. And now that I have to take care of them, I run into all sorts of issues.
    It happened many times that I connected a bunch of computers to a multicast session, started the session only to see that one of the computers had a faulty cable and it connected only at 10Mbps. So the deployment took something like 8 hours. I had to leave it overnight.

    Would it be very complicated to display the connection speed on, for example, the multicast login page? That way, before starting the multicast, I can quickly review connection speeds and replace the cable if needed.


  • @Sebastian-Roth

    No, unfortunately not. I was so busy these last few days that couldn’t make some time to experiment.
    As I said, I just took over the management of our university networks and setting everything right will take some time.
    But I have this issue on my to-do list because O am directly interested so I didn’t forget. I’ll get back here when I have news.

  • Senior Developer

    @andreiv Any news on this?

  • @Sebastian-Roth

    First, thanks for the effort. Sure, I’ll try what you suggest and see what I can come up with.

  • Senior Developer

    @andreiv I played a bit with that but have not come up with a proper solution yet. The point where you need the information (before or at login time) we are bound to get the connection speed within the iPXE environment. Although it can do lots of things I have not found any hint on it being able to display the connection speed.

    Altough I know iPXE is capable of doing auto-negotiation on most network cards it’s interesting it doesn’t seem to provide this information to the outside world.

    What I came across is the driver speed test: http://ipxe.org/dev/drvtest/speed
    Possibly we could include that to measure download speed beforehand. Not great but maybe better than nothing.

    Can you please go ahead and do a bit of testing in your environment. For that go to the FOG web UI -> FOG Configuration -> iPXE Menu Item Settings -> fog.multijoin: here the Parameters section starts like this:

    param mac0 ${net0/mac}

    Now edit that and make it read:

    param mac0 ${net0/mac}

    Now when you boot up a client and select Multicast from the menu you will be dropped to the iPXE shell. Here you can test all the various iPXE commands and especially see what you can get out of the driver speed test things: time imgfetch ${boot-url}/service/ipxe/init.xz ; imgfree (takes around 1.4 to 1.6 seconds in my VM environment - see if you can get a clear difference in your setup between 10 MBit/s and 100 MBit/s links)

  • In the beginning I used group multicast but since people here have the bad habit of moving computers around between labs, I gave up managing groups.
    Now I just join them to a multicast session.

    Another advantage of the multicast session join is that I see how many computers can actually join and set up the session for that particular number of computers.

    It happened to me in the past, when using group multicast, that one (or more) computer(s) had cable issues and was unable to join, so the session didn’t start because not all group members joined.

  • Senior Developer

    @andreiv Nice idea. But what if you schedule multicast as a group task? No login or any other User interaction is needed then.